linalg.py 132.8 KB
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#   Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
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import numpy as np
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import paddle
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from paddle import _C_ops
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from paddle.common_ops_import import VarDesc

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from ..common_ops_import import Variable
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from ..fluid.data_feeder import (
    check_dtype,
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    check_type,
    check_variable_and_dtype,
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)
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from ..framework import LayerHelper, in_dynamic_mode
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from .creation import full
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from .manipulation import cast
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from .math import _get_reduce_axis
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__all__ = []

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# Consistent with kDefaultDim from C++ Backend
K_DEFAULT_DIM = 9

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def transpose(x, perm, name=None):
    """
    Permute the data dimensions of `input` according to `perm`.

    The `i`-th dimension  of the returned tensor will correspond to the
    perm[i]-th dimension of `input`.

    Args:
        x (Tensor): The input Tensor. It is a N-D Tensor of data types bool, float32, float64, int32.
        perm (list|tuple): Permute the input according to the data of perm.
        name (str): The name of this layer. It is optional.

    Returns:
        Tensor: A transposed n-D Tensor, with data type being bool, float32, float64, int32, int64.

    For Example:

        .. code-block:: text

         x = [[[ 1  2  3  4] [ 5  6  7  8] [ 9 10 11 12]]
             [[13 14 15 16] [17 18 19 20] [21 22 23 24]]]
         shape(x) =  [2,3,4]

         # Example 1
         perm0 = [1,0,2]
         y_perm0 = [[[ 1  2  3  4] [13 14 15 16]]
                   [[ 5  6  7  8]  [17 18 19 20]]
                   [[ 9 10 11 12]  [21 22 23 24]]]
         shape(y_perm0) = [3,2,4]

         # Example 2
         perm1 = [2,1,0]
         y_perm1 = [[[ 1 13] [ 5 17] [ 9 21]]
                   [[ 2 14] [ 6 18] [10 22]]
                   [[ 3 15]  [ 7 19]  [11 23]]
                   [[ 4 16]  [ 8 20]  [12 24]]]
         shape(y_perm1) = [4,3,2]

    Examples:

        .. code-block:: python

            import paddle

            x = paddle.randn([2, 3, 4])
            x_transposed = paddle.transpose(x, perm=[1, 0, 2])
            print(x_transposed.shape)
            # [3L, 2L, 4L]

    """
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    if in_dynamic_mode():
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        return _C_ops.transpose(x, perm)
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    else:
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        check_variable_and_dtype(
            x,
            'x',
            [
                'bool',
                'float16',
                'float32',
                'float64',
                'int32',
                'int64',
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                'uint16',
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                'complex64',
                'complex128',
            ],
            'transpose',
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        )
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        check_type(perm, 'perm', (list, tuple), 'transpose')
        if isinstance(perm, tuple):
            perm = list(perm)
        if len(perm) != len(x.shape):
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            raise ValueError(
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                "Input(perm) is the permutation of dimensions of Input(x), "
                "its length should be equal to dimensions of Input(x), "
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                "but received dimension of Input(x) is {}, "
                "the length of Input(perm) is {}.".format(
                    len(x.shape), len(perm)
                )
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            )
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        for idx, dim in enumerate(perm):
            if dim >= len(x.shape):
                raise ValueError(
                    "Each element in Input(perm) should be less than Input(x)'s dimension, "
                    "but %d-th element in Input(perm) is %d which exceeds Input(x)'s "
                    "dimension %d." % (idx, perm[idx], len(x.shape))
                )
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        helper = LayerHelper('transpose', **locals())
        out = helper.create_variable_for_type_inference(x.dtype)
        x_shape = helper.create_variable_for_type_inference(x.dtype)
        helper.append_op(
            type='transpose2',
            inputs={'X': [x]},
            outputs={'Out': [out], 'XShape': [x_shape]},
            attrs={'axis': perm},
        )
        return out
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def matmul(x, y, transpose_x=False, transpose_y=False, name=None):
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    """
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    Applies matrix multiplication to two tensors. `matmul` follows
    the complete broadcast rules,
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    and its behavior is consistent with `np.matmul`.
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    Currently, the input tensors' number of dimensions can be any, `matmul` can be used to
    achieve the `dot`, `matmul` and `batchmatmul`.
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    The actual behavior depends on the shapes of :math:`x`, :math:`y` and the
    flag values of :attr:`transpose_x`, :attr:`transpose_y`. Specifically:

    - If a transpose flag is specified, the last two dimensions of the tensor
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      are transposed. If the tensor is ndim-1 of shape, the transpose is invalid. If the tensor
      is ndim-1 of shape :math:`[D]`, then for :math:`x` it is treated as :math:`[1, D]`, whereas
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      for :math:`y` it is the opposite: It is treated as :math:`[D, 1]`.

    The multiplication behavior depends on the dimensions of `x` and `y`. Specifically:

    - If both tensors are 1-dimensional, the dot product result is obtained.

    - If both tensors are 2-dimensional, the matrix-matrix product is obtained.

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    - If the `x` is 1-dimensional and the `y` is 2-dimensional,
      a `1` is prepended to its dimension in order to conduct the matrix multiply.
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      After the matrix multiply, the prepended dimension is removed.
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    - If the `x` is 2-dimensional and `y` is 1-dimensional,
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      the matrix-vector product is obtained.

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    - If both arguments are at least 1-dimensional and at least one argument
      is N-dimensional (where N > 2), then a batched matrix multiply is obtained.
      If the first argument is 1-dimensional, a 1 is prepended to its dimension
      in order to conduct the batched matrix multiply and removed after.
      If the second argument is 1-dimensional, a 1 is appended to its
      dimension for the purpose of the batched matrix multiple and removed after.
      The non-matrix (exclude the last two dimensions) dimensions are
      broadcasted according the broadcast rule.
      For example, if input is a (j, 1, n, m) tensor and the other is a (k, m, p) tensor,
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      out will be a (j, k, n, p) tensor.
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    Args:
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        x (Tensor): The input tensor which is a Tensor.
        y (Tensor): The input tensor which is a Tensor.
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        transpose_x (bool, optional): Whether to transpose :math:`x` before multiplication.
        transpose_y (bool, optional): Whether to transpose :math:`y` before multiplication.
        name(str, optional): A name for this layer(optional). If set None, the layer
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            will be named automatically.

    Returns:
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        Tensor: The output Tensor.
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    Examples:

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        .. code-block:: python

            import paddle

            # vector * vector
            x = paddle.rand([10])
            y = paddle.rand([10])
            z = paddle.matmul(x, y)
            print(z.shape)
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            # ()
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            # matrix * vector
            x = paddle.rand([10, 5])
            y = paddle.rand([5])
            z = paddle.matmul(x, y)
            print(z.shape)
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            # (10,)
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            # batched matrix * broadcasted vector
            x = paddle.rand([10, 5, 2])
            y = paddle.rand([2])
            z = paddle.matmul(x, y)
            print(z.shape)
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            # (10, 5)
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            # batched matrix * batched matrix
            x = paddle.rand([10, 5, 2])
            y = paddle.rand([10, 2, 5])
            z = paddle.matmul(x, y)
            print(z.shape)
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            # (10, 5, 5)
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            # batched matrix * broadcasted matrix
            x = paddle.rand([10, 1, 5, 2])
            y = paddle.rand([1, 3, 2, 5])
            z = paddle.matmul(x, y)
            print(z.shape)
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            # (10, 3, 5, 5)
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    """
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    if in_dynamic_mode():
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        return _C_ops.matmul(x, y, transpose_x, transpose_y)
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    else:
        attrs = {
            'trans_x': transpose_x,
            'trans_y': transpose_y,
        }
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        def __check_input(x, y):
            var_names = {'x': x, 'y': y}
            for name, val in var_names.items():
                check_variable_and_dtype(
                    val,
                    name,
                    [
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                        'uint16',
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                        'float16',
                        'float32',
                        'float64',
                        'complex64',
                        'complex128',
                    ],
                    'matmul',
                )
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        __check_input(x, y)
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        helper = LayerHelper('matmul_v2', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
        helper.append_op(
            type='matmul_v2',
            inputs={'X': x, 'Y': y},
            outputs={'Out': out},
            attrs=attrs,
        )
        return out
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def norm(x, p='fro', axis=None, keepdim=False, name=None):
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    """
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    Returns the matrix norm (Frobenius) or vector norm (the 1-norm, the Euclidean
    or 2-norm, and in general the p-norm for p > 0) of a given tensor.

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    Note:
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        This norm API is different from `numpy.linalg.norm`.
        This api supports high-order input tensors (rank >= 3), and certain axis need to be pointed out to calculate the norm.
        But `numpy.linalg.norm` only supports 1-D vector or 2-D matrix as input tensor.
        For p-order matrix norm, this api actually treats matrix as a flattened vector to calculate the vector norm, NOT REAL MATRIX NORM.

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    Args:
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        x (Tensor): The input tensor could be N-D tensor, and the input data
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            type could be float32 or float64.
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        p (float|string, optional): Order of the norm. Supported values are `fro`, `0`, `1`, `2`,
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            `inf`, `-inf` and any positive real number yielding the corresponding p-norm. Not supported: ord < 0 and nuclear norm.
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            Default value is `fro`.
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        axis (int|list|tuple, optional): The axis on which to apply norm operation. If axis is int
            or list(int)/tuple(int)  with only one element, the vector norm is computed over the axis.
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            If `axis < 0`, the dimension to norm operation is rank(input) + axis.
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            If axis is a list(int)/tuple(int) with two elements, the matrix norm is computed over the axis.
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            Default value is `None`.
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        keepdim (bool, optional): Whether to reserve the reduced dimension in the
            output Tensor. The result tensor will have fewer dimension
            than the :attr:`input` unless :attr:`keepdim` is true, default
            value is False.
        name (str, optional): The default value is None. Normally there is no need for
            user to set this property. For more information, please refer to :ref:`api_guide_Name`.

    Returns:
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        Tensor: results of norm operation on the specified axis of input tensor,
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        it's data type is the same as input's Tensor.
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    Examples:
        .. code-block:: python
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            import paddle
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            x = paddle.arange(24, dtype="float32").reshape([2, 3, 4]) - 12
            # x: Tensor(shape=[2, 3, 4], dtype=float32, place=Place(cpu), stop_gradient=True,
            #          [[[-12., -11., -10., -9. ],
            #            [-8. , -7. , -6. , -5. ],
            #            [-4. , -3. , -2. , -1. ]],

            #           [[ 0. ,  1. ,  2. ,  3. ],
            #            [ 4. ,  5. ,  6. ,  7. ],
            #            [ 8. ,  9. ,  10.,  11.]]])
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            # compute frobenius norm along last two dimensions.
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            out_fro = paddle.linalg.norm(x, p='fro', axis=[0,1])
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            # out_fro: Tensor(shape=[4], dtype=float32, place=Place(cpu), stop_gradient=True,
            #                 [17.43559647, 16.91153526, 16.73320007, 16.91153526])
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            # compute 2-order vector norm along last dimension.
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            out_pnorm = paddle.linalg.norm(x, p=2, axis=-1)
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            # out_pnorm: Tensor(shape=[2, 3], dtype=float32, place=Place(cpu), stop_gradient=True,
            #                [[21.11871147, 13.19090557, 5.47722578 ],
            #                 [3.74165750 , 11.22497177, 19.13112640]])
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            # compute 2-order  norm along [0,1] dimension.
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            out_pnorm = paddle.linalg.norm(x, p=2, axis=[0,1])
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            # out_pnorm: Tensor(shape=[4], dtype=float32, place=Place(cpu), stop_gradient=True,
            #                  [17.43559647, 16.91153526, 16.73320007, 16.91153526])
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            # compute inf-order  norm
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            out_pnorm = paddle.linalg.norm(x, p=float("inf"))
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            # out_pnorm  = Tensor(shape=[], dtype=float32, place=Place(cpu), stop_gradient=True,
            #                    12.)
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            out_pnorm = paddle.linalg.norm(x, p=float("inf"), axis=0)
            # out_pnorm: Tensor(shape=[3, 4], dtype=float32, place=Place(cpu), stop_gradient=True,
            #                 [[12., 11., 10., 9. ],
            #                  [8. , 7. , 6. , 7. ],
            #                  [8. , 9. , 10., 11.]])
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            # compute -inf-order  norm
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            out_pnorm = paddle.linalg.norm(x, p=-float("inf"))
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            # out_pnorm: Tensor(shape=[], dtype=float32, place=Place(cpu), stop_gradient=True,
            #                  0.)
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            out_pnorm = paddle.linalg.norm(x, p=-float("inf"), axis=0)
            # out_pnorm: Tensor(shape=[3, 4], dtype=float32, place=Place(cpu), stop_gradient=True,
            #                  [[0., 1., 2., 3.],
            #                  [4., 5., 6., 5.],
            #                  [4., 3., 2., 1.]])
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    """

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    def frobenius_norm(input, dim=None, keepdim=False, name=None):
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        """
        The frobenius norm OP is to calculate the frobenius norm of certain two dimensions of Tensor `input`.
        Args:
          input (Variable): Tensor, data type float32, float64.
          dim (list, optional): None for last two dimensions.
          keepdim (bool, optional): Whether keep the dimensions as the `input`, Default False.
        """
        if dim is not None and not (isinstance(dim, list) and len(dim) == 2):
            raise ValueError(
                "The dim of frobenius norm op should be None or two elements list!"
            )
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        if in_dynamic_mode():
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            if dim is None:
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                return _C_ops.frobenius_norm(input, [], keepdim, True)
            return _C_ops.frobenius_norm(input, dim, keepdim, False)
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        else:
            attrs = {'dim': dim, 'keep_dim': keepdim, 'reduce_all': False}
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            if dim is None:
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                attrs['reduce_all'] = True
            check_variable_and_dtype(
                input, 'input', ['float32', 'float64'], 'frobenius_norm'
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            )
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            helper = LayerHelper('frobenius_norm', **locals())
            out = helper.create_variable_for_type_inference(
                dtype=helper.input_dtype()
            )
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            helper.append_op(
                type='frobenius_norm',
                inputs={'X': input},
                outputs={'Out': out},
                attrs=attrs,
            )
            return out
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    def vector_norm(
        input, porder=None, axis=None, keepdim=False, asvector=False, name=None
    ):
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        """
        Calculate the p-order vector norm for certain  dimension of Tensor `input`.
        Args:
          input (Variable): Tensor, data type float32, float64.
          porder (float, optional): None for porder=2.0.
          axis (int, optional): None for last dimension.
          keepdim (bool, optional): Whether keep the dimensions as the `input`, Default False.
        """
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        if in_dynamic_mode():
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            if axis is None:
                axis = -1
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            return _C_ops.p_norm(input, porder, axis, 1e-12, keepdim, asvector)
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        else:
            if porder is not None:
                check_type(porder, 'porder', (float, int), 'p_norm')
            if axis is not None:
                check_type(axis, 'axis', (int), 'p_norm')
            check_variable_and_dtype(
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                input,
                'input',
                ['float16', 'uint16', 'float32', 'float64'],
                'p_norm',
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            )
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            attrs = {
                'axis': axis if axis is not None else -1,
                'porder': float(porder) if porder is not None else 2.0,
                'keepdim': keepdim,
                'asvector': asvector,
                'epsilon': 1e-12,
            }
            helper = LayerHelper('p_norm', **locals())
            out = helper.create_variable_for_type_inference(
                dtype=helper.input_dtype()
            )
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            helper.append_op(
                type='p_norm',
                inputs={'X': input},
                outputs={'Out': out},
                attrs=attrs,
            )
            return out
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    def inf_norm(
        input, porder=None, axis=axis, keepdim=False, asvector=False, name=None
    ):
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        if in_dynamic_mode():
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            out = _C_ops.abs(input)
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            if porder == np.float64('inf'):
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                return _C_ops.max(out, axis, keepdim)
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            else:
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                return _C_ops.min(out, axis, keepdim)
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        else:
            helper = LayerHelper('inf_norm', **locals())
            out = helper.create_variable_for_type_inference(
                dtype=helper.input_dtype()
            )
            helper.append_op(
                type='abs', inputs={'X': input}, outputs={'Out': out}
            )
            reduce_out = helper.create_variable_for_type_inference(
                dtype=helper.input_dtype()
            )
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            reduce_all, axis = _get_reduce_axis(axis, x)
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            reduce_type = (
                'reduce_max' if porder == np.float64('inf') else 'reduce_min'
            )
            helper.append_op(
                type=reduce_type,
                inputs={'X': out},
                outputs={'Out': reduce_out},
                attrs={
                    'dim': axis,
                    'keep_dim': keepdim,
                    'reduce_all': reduce_all,
                },
            )
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            return reduce_out
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    def p_matrix_norm(input, porder=1.0, axis=axis, keepdim=False, name=None):
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        """
        NOTE:
            This function actually treats the matrix as flattened vector to calculate vector norm instead of matrix norm.
        """
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        if in_dynamic_mode():
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            abs_out = _C_ops.abs(input)
            pow_out = _C_ops.pow(abs_out, porder)
            sum_out = _C_ops.sum(pow_out, axis, None, keepdim)
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            out = _C_ops.pow(sum_out, float(1.0 / porder))
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            return out

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        block = LayerHelper('norm', **locals())
        out = block.create_variable_for_type_inference(
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            dtype=block.input_dtype()
        )
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        abs_out = block.create_variable_for_type_inference(
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            dtype=block.input_dtype()
        )
        block.append_op(
            type='abs', inputs={'X': input}, outputs={'Out': abs_out}
        )
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        pow_out = block.create_variable_for_type_inference(
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            dtype=block.input_dtype()
        )
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        block.append_op(
            type='pow',
            inputs={'X': abs_out},
            outputs={'Out': pow_out},
            attrs={'factor': porder},
        )
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        sum_out = block.create_variable_for_type_inference(
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            dtype=block.input_dtype()
        )
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        reduce_all, axis = _get_reduce_axis(axis, x)
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        block.append_op(
            type='reduce_sum',
            inputs={'X': pow_out},
            outputs={'Out': sum_out},
            attrs={
                'dim': axis,
                'keep_dim': keepdim,
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                'reduce_all': reduce_all,
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            },
        )
        block.append_op(
            type='pow',
            inputs={'X': sum_out},
            outputs={'Out': out},
            attrs={'factor': float(1.0 / porder)},
        )
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        return out

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    if axis is None and p is not None:
        if isinstance(p, str):
            if p == "fro":
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                return frobenius_norm(x, dim=axis, keepdim=keepdim, name=name)
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            else:
                raise ValueError(
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                    f"only valid string values are 'fro', found {p}"
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                )
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        elif isinstance(p, (int, float)):
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            return vector_norm(
                x,
                porder=p,
                axis=axis,
                keepdim=keepdim,
                asvector=True,
                name=name,
            )
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        else:
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            raise ValueError(
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                f"only valid p type is string or float, found {type(p)}"
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            )
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    if isinstance(axis, tuple):
        axis = list(axis)
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    if isinstance(axis, list) and len(axis) == 1:
        axis = axis[0]

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    # calculate vector norm, where axis is int or list with only one integer
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    if isinstance(axis, int):
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        if isinstance(p, str):
            if p == "fro":
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                return vector_norm(
                    x,
                    porder=2,
                    axis=axis,
                    keepdim=keepdim,
                    asvector=False,
                    name=name,
                )
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            else:
                raise ValueError(
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                    f"only valid string values are 'fro', found {p}"
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                )
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        elif isinstance(p, (int, float)):
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            return vector_norm(
                x,
                axis=axis,
                porder=p,
                keepdim=keepdim,
                asvector=False,
                name=name,
            )
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        else:
            raise ValueError(
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                "unspport p for p-order vector norm. except float, found {}".format(
                    p
                )
            )
    # calculate matrix norm, where axis is list with two integers
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    elif isinstance(axis, list) and len(axis) == 2:
        if p == "fro":
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            return frobenius_norm(x, dim=axis, keepdim=keepdim, name=name)
        elif p == np.inf or p == -np.inf:
            return inf_norm(x, porder=p, axis=axis, keepdim=keepdim, name=name)
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        elif p == 0:
            raise ValueError(
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                "just support axis type int or list (length of list <=1) if p = 0, found {}".format(
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                    axis
                )
            )
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        else:
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            return p_matrix_norm(
                x, porder=p, axis=axis, keepdim=keepdim, name=name
            )
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    else:
        raise ValueError(
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            "except axis type int or list (length of list <=2), found {}".format(
                axis
            )
        )
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def dist(x, y, p=2, name=None):
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    r"""
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    Returns the p-norm of (x - y). It is not a norm in a strict sense, only as a measure
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    of distance. The shapes of x and y must be broadcastable. The definition is as follows, for
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    details, please refer to the `Introduction to Tensor <../../guides/beginner/tensor_en.html#chapter5-broadcasting-of-tensor>`_:
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    - Each input has at least one dimension.
    - Match the two input dimensions from back to front, the dimension sizes must either be equal, one of them is 1, or one of them does not exist.

    Where, z = x - y, the shapes of x and y are broadcastable, then the shape of z can be
    obtained as follows:

    1. If the number of dimensions of x and y are not equal, prepend 1 to the dimensions of the
    tensor with fewer dimensions.

    For example, The shape of x is [8, 1, 6, 1], the shape of y is [7, 1, 5], prepend 1 to the
    dimension of y.

    x (4-D Tensor):  8 x 1 x 6 x 1

    y (4-D Tensor):  1 x 7 x 1 x 5

    2. Determine the size of each dimension of the output z: choose the maximum value from the
    two input dimensions.

    z (4-D Tensor):  8 x 7 x 6 x 5

    If the number of dimensions of the two inputs are the same, the size of the output can be
    directly determined in step 2. When p takes different values, the norm formula is as follows:
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    When p = 0, defining $0^0=0$, the zero-norm of z is simply the number of non-zero elements of z.

    .. math::

        ||z||_{0}=\lim_{p \\rightarrow 0}\sum_{i=1}^{m}|z_i|^{p}

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    When p = inf, the inf-norm of z is the maximum element of the absolute value of z.
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    .. math::

        ||z||_\infty=\max_i |z_i|

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    When p = -inf, the negative-inf-norm of z is the minimum element of the absolute value of z.
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    .. math::

        ||z||_{-\infty}=\min_i |z_i|

    Otherwise, the p-norm of z follows the formula,

    .. math::

        ||z||_{p}=(\sum_{i=1}^{m}|z_i|^p)^{\\frac{1}{p}}

    Args:
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        x (Tensor): 1-D to 6-D Tensor, its data type is bfloat16, float16, float32 or float64.
        y (Tensor): 1-D to 6-D Tensor, its data type is bfloat16, float16, float32 or float64.
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        p (float, optional): The norm to be computed, its data type is float32 or float64. Default: 2.
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        name (str, optional): The default value is `None`. Normally there is no need for
            user to set this property. For more information, please refer to :ref:`api_guide_Name`.
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    Returns:
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        Tensor: Tensor that is the p-norm of (x - y).
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    Examples:
        .. code-block:: python

            import paddle

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            x = paddle.to_tensor([[3, 3],[3, 3]], dtype="float32")
            y = paddle.to_tensor([[3, 3],[3, 1]], dtype="float32")
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            out = paddle.dist(x, y, 0)
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            print(out) # out = 1.
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            out = paddle.dist(x, y, 2)
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            print(out) # out = 2.
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            out = paddle.dist(x, y, float("inf"))
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            print(out) # out = 2.
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            out = paddle.dist(x, y, float("-inf"))
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            print(out) # out = 0.
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    """
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    if in_dynamic_mode():
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        return _C_ops.dist(x, y, p)
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    check_variable_and_dtype(
        x, 'dtype', ['bfloat16', 'float16', 'float32', 'float64'], 'dist'
    )
    check_variable_and_dtype(
        y, 'dtype', ['bfloat16', 'float16', 'float32', 'float64'], 'dist'
    )
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    check_type(p, 'p', (float, int), 'dist')
    helper = LayerHelper("dist", **locals())
    out = helper.create_variable_for_type_inference(x.dtype)

    inputs = {"X": [x], "Y": [y]}
    outputs = {'Out': [out]}
    attrs = {"p": float(p)}
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    helper.append_op(
        type='dist', inputs=inputs, outputs={'Out': out}, attrs=attrs
    )
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    return out
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def cond(x, p=None, name=None):
    """

    Computes the condition number of a matrix or batches of matrices with respect to a matrix norm ``p``.

    Args:
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        x (Tensor): The input tensor could be tensor of shape ``(*, m, n)`` where ``*`` is zero or more batch dimensions
            for ``p`` in ``(2, -2)``, or of shape ``(*, n, n)`` where every matrix is invertible for any supported ``p``.
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            And the input data type could be ``float32`` or ``float64``.
        p (float|string, optional): Order of the norm. Supported values are `fro`, `nuc`, `1`, `-1`, `2`, `-2`,
            `inf`, `-inf`. Default value is `None`, meaning that the order of the norm is `2`.
        name (str, optional): The default value is `None`. Normally there is no need for
            user to set this property. For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Tensor: computing results of condition number, its data type is the same as input Tensor ``x``.

    Examples:
        .. code-block:: python

            import paddle

            x = paddle.to_tensor([[1., 0, -1], [0, 1, 0], [1, 0, 1]])

            # compute conditional number when p is None
            out = paddle.linalg.cond(x)
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        1.41421342)
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            # compute conditional number when order of the norm is 'fro'
            out_fro = paddle.linalg.cond(x, p='fro')
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        3.16227770)
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            # compute conditional number when order of the norm is 'nuc'
            out_nuc = paddle.linalg.cond(x, p='nuc')
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        9.24263859)
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            # compute conditional number when order of the norm is 1
            out_1 = paddle.linalg.cond(x, p=1)
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        2.)
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            # compute conditional number when order of the norm is -1
            out_minus_1 = paddle.linalg.cond(x, p=-1)
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        1.)
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            # compute conditional number when order of the norm is 2
            out_2 = paddle.linalg.cond(x, p=2)
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        1.41421342)
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            # compute conditional number when order of the norm is -1
            out_minus_2 = paddle.linalg.cond(x, p=-2)
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        0.70710683)
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            # compute conditional number when order of the norm is inf
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            out_inf = paddle.linalg.cond(x, p=float("inf"))
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        2.)
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            # compute conditional number when order of the norm is -inf
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            out_minus_inf = paddle.linalg.cond(x, p=-float("inf"))
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        1.)
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            a = paddle.randn([2, 4, 4])
            # Tensor(shape=[2, 4, 4], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        [[[-0.06784091, -0.07095790,  1.31792855, -0.58959651],
            #          [ 0.20818676, -0.85640615, -0.89998871, -1.47439921],
            #          [-0.49132481,  0.42250812, -0.77383220, -2.19794774],
            #          [-0.33551720, -1.70003879, -1.09795380, -0.63737559]],

            #         [[ 1.12026262, -0.16119350, -1.21157813,  2.74383283],
            #          [-0.15999718,  0.18798758, -0.69392562,  1.35720372],
            #          [-0.53013402, -2.26304483,  1.40843511, -1.02288902],
            #          [ 0.69533503,  2.05261683, -0.02251151, -1.43127477]]])

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            a_cond_fro = paddle.linalg.cond(a, p='fro')
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            # Tensor(shape=[2], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        [8.86691189 , 75.23817444])

            b = paddle.randn([2, 3, 4])
            # Tensor(shape=[2, 3, 4], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        [[[-0.43754861,  1.80796063, -0.78729683, -1.82264030],
            #          [-0.27670753,  0.06620564,  0.29072434, -0.31155765],
            #          [ 0.34123746, -0.05444612,  0.05001324, -1.46877074]],

            #         [[-0.64331555, -1.51103854, -1.26277697, -0.68024760],
            #          [ 2.59375715, -1.06665540,  0.96575671, -0.73330832],
            #          [-0.47064447, -0.23945692, -0.95150250, -1.07125998]]])
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            b_cond_2 = paddle.linalg.cond(b, p=2)
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            # Tensor(shape=[2], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        [6.64228773, 3.89068866])
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    """

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    def mat_norm(input, porder=1.0, axis=None):
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        """
        NOTE:
            Calculate the matrix norm of a square matrix or batches of square matrices,
            when porder is in (1, -1, inf, -inf)
        """
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        if in_dynamic_mode():
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            abs_out = _C_ops.abs(input)
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            sum_out = _C_ops.sum(abs_out, axis, None, False)
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            if porder == 1 or porder == np.inf:
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                return _C_ops.max(sum_out, [-1], False)
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            if porder == -1 or porder == -np.inf:
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                return _C_ops.min(sum_out, [-1], False)
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        else:
            block = LayerHelper('norm', **locals())
            abs_out = block.create_variable_for_type_inference(
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                dtype=block.input_dtype()
            )
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            sum_out = block.create_variable_for_type_inference(
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                dtype=block.input_dtype()
            )
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            out = block.create_variable_for_type_inference(
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                dtype=block.input_dtype()
            )
            block.append_op(
                type='abs', inputs={'X': input}, outputs={'Out': abs_out}
            )
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            reduce_all, axis = _get_reduce_axis(axis, x)
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            block.append_op(
                type='reduce_sum',
                inputs={'X': abs_out},
                outputs={'Out': sum_out},
                attrs={
                    'dim': axis,
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                    'keep_dim': False,
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                    'reduce_all': reduce_all,
                },
            )
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            if porder == 1 or porder == np.inf:
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                block.append_op(
                    type='reduce_max',
                    inputs={'X': sum_out},
                    outputs={'Out': out},
                    attrs={
                        'dim': [-1],
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                        'keep_dim': False,
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                        'reduce_all': reduce_all,
                    },
                )
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            if porder == -1 or porder == -np.inf:
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                block.append_op(
                    type='reduce_min',
                    inputs={'X': sum_out},
                    outputs={'Out': out},
                    attrs={
                        'dim': [-1],
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                        'keep_dim': False,
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                        'reduce_all': reduce_all,
                    },
                )
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            return out
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    def fro_norm(input, porder=2, axis=[-1]):
        """
        NOTE:
            Calculate the frobenius norm of a square matrix or batches of square matrices.
        """
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        if in_dynamic_mode():
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            pow_out = _C_ops.pow(input, porder)
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            sum_out_1 = _C_ops.sum(pow_out, axis, None, False)
            sum_out_2 = _C_ops.sum(sum_out_1, axis, None, False)
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            return _C_ops.pow(sum_out_2, float(1.0 / porder))
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        else:
            block = LayerHelper('norm', **locals())
            pow_out = block.create_variable_for_type_inference(
                dtype=block.input_dtype()
            )
            sum_out_1 = block.create_variable_for_type_inference(
                dtype=block.input_dtype()
            )
            sum_out_2 = block.create_variable_for_type_inference(
                dtype=block.input_dtype()
            )
            out = block.create_variable_for_type_inference(
                dtype=block.input_dtype()
            )
            block.append_op(
                type='pow',
                inputs={'X': input},
                outputs={'Out': pow_out},
                attrs={'factor': porder},
            )
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            reduce_all, axis = _get_reduce_axis(axis, x)
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            block.append_op(
                type='reduce_sum',
                inputs={'X': pow_out},
                outputs={'Out': sum_out_1},
                attrs={
                    'dim': axis,
                    'keep_dim': False,
                    'reduce_all': reduce_all,
                },
            )
            block.append_op(
                type='reduce_sum',
                inputs={'X': sum_out_1},
                outputs={'Out': sum_out_2},
                attrs={
                    'dim': axis,
                    'keep_dim': False,
                    'reduce_all': reduce_all,
                },
            )
            block.append_op(
                type='pow',
                inputs={'X': sum_out_2},
                outputs={'Out': out},
                attrs={'factor': float(1.0 / porder)},
            )
            return out
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    def svd_norm(input, porder, axis=[-1]):
        """
        NOTE:
            Calculate the matrix norm, which is related to singular values, of a matrix
            or batches of matrices, including nuclear norm, 2-norm and (-2)-norm.
        """
        u, s, vh = svd(input, full_matrices=False)

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        if in_dynamic_mode():
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            if porder == "nuc":
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                return _C_ops.sum(s, axis, None, False)
            max_out = _C_ops.max(s, axis, False)
            min_out = _C_ops.min(s, axis, False)
            if porder == 2:
                return _C_ops.divide(max_out, min_out)
            if porder == -2:
                return _C_ops.divide(min_out, max_out)
        else:
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            reduce_all, axis = _get_reduce_axis(axis, x)
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            block = LayerHelper('norm', **locals())
            out = block.create_variable_for_type_inference(
                dtype=block.input_dtype()
            )
            if porder == "nuc":
                block.append_op(
                    type='reduce_sum',
                    inputs={'X': s},
                    outputs={'Out': out},
                    attrs={
                        'dim': axis,
                        'keep_dim': False,
                        'reduce_all': reduce_all,
                    },
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                )
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                return out
            max_out = block.create_variable_for_type_inference(
                dtype=block.input_dtype()
            )
            min_out = block.create_variable_for_type_inference(
                dtype=block.input_dtype()
            )
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            block.append_op(
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                type='reduce_max',
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                inputs={'X': s},
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                outputs={'Out': max_out},
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                attrs={
                    'dim': axis,
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                    'keep_dim': False,
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                    'reduce_all': reduce_all,
                },
            )
            block.append_op(
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                type='reduce_min',
                inputs={'X': s},
                outputs={'Out': min_out},
                attrs={
                    'dim': axis,
                    'keep_dim': False,
                    'reduce_all': reduce_all,
                },
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            )
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            if porder == 2:
                block.append_op(
                    type='elementwise_div',
                    inputs={'X': max_out, 'Y': min_out},
                    outputs={'Out': out},
                    attrs={'aixs': axis, 'use_mkldnn': False},
                )
                return out
            if porder == -2:
                block.append_op(
                    type='elementwise_div',
                    inputs={'X': min_out, 'Y': max_out},
                    outputs={'Out': out},
                    attrs={'aixs': axis, 'use_mkldnn': False},
                )
                return out
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    def empty_tensor(input, shape):
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        if in_dynamic_mode():
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            return input.reshape(shape)
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        raise ValueError(
            "only support x is nonempty tensor in static graph mode"
        )
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    x_shape = list(x.shape)
    if not len(x_shape) >= 2:
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        raise ValueError(
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            "input should be a matrix or batches of matrices, "
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            + f"but the dimention of received input is {len(x_shape)}"
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        )
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    if p is None:
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        p = 2
    x_size = 0 if (0 in x_shape) else 1
    if p in ("fro", "nuc", 1, -1, np.inf, -np.inf):
        if x_shape[len(x_shape) - 1] == x_shape[len(x_shape) - 2]:
            if x_size == 0:
                return empty_tensor(x, x_shape[:-2])
            x_inv = x.inverse()
            if p == "fro":
                return fro_norm(x) * fro_norm(x_inv)
            if p == "nuc":
                return svd_norm(x, p) * svd_norm(x_inv, p)
            if p in (1, -1):
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                return mat_norm(x, porder=p, axis=[-2]) * mat_norm(
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                    x_inv, porder=p, axis=[-2]
                )
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            if p in (np.inf, -np.inf):
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                return mat_norm(x, porder=p, axis=[-1]) * mat_norm(
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                    x_inv, porder=p, axis=[-1]
                )
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        else:
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            raise ValueError(
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                f"only support p is {p} when input is a "
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                + "square matrix or batches of square matrices"
            )
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    elif p in (2, -2):
        if x_size == 0:
            return empty_tensor(x, x_shape[:-2])
        return svd_norm(x, porder=p)
    else:
        raise ValueError(
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            f"unsupported {p} for p, only supporting ('fro', 'nuc', "
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            + "1, -1, 2, -2, inf, -inf) or none"
        )
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def dot(x, y, name=None):
    """
    This operator calculates inner product for vectors.
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    Note:
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       Support 1-d and 2-d Tensor. When it is 2d, the first dimension of this matrix
       is the batch dimension, which means that the vectors of multiple batches are dotted.
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    Parameters:
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        x(Tensor): 1-D or 2-D ``Tensor``. Its dtype should be ``float32``, ``float64``, ``int32``, ``int64``, ``complex64``, ``complex128``
        y(Tensor): 1-D or 2-D ``Tensor``. Its dtype soulde be ``float32``, ``float64``, ``int32``, ``int64``, ``complex64``, ``complex128``
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        name(str, optional): Name of the output. Default is None. It's used to print debug info for developers. Details: :ref:`api_guide_Name`

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    Returns:
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        Tensor: the calculated result Tensor.
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    Examples:

    .. code-block:: python

        import paddle
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        # 1-D Tensor * 1-D Tensor
        x = paddle.to_tensor([1, 2, 3])
        y = paddle.to_tensor([4, 5, 6])
        z = paddle.dot(x, y)
1100
        print(z)  # 32
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        # 2-D Tensor * 2-D Tensor
        x = paddle.to_tensor([[1, 2, 3], [2, 4, 6]])
        y = paddle.to_tensor([[4, 5, 6], [4, 5, 6]])
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        z = paddle.dot(x, y)
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        print(z)  # [32, 64]
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    """
1109
    if in_dynamic_mode():
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        return _C_ops.dot(x, y)
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    else:
        op_type = 'dot'
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        assert x is not None, f'x cannot be None in {op_type}'
        assert y is not None, f'y cannot be None in {op_type}'
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        check_variable_and_dtype(
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            x,
            'x',
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            [
                'float16',
                'uint16',
                'float32',
                'float64',
                'int32',
                'int64',
                'complex64',
                'complex128',
            ],
1130
            op_type,
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        )
        check_variable_and_dtype(
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            y,
            'y',
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            [
                'float16',
                'uint16',
                'float32',
                'float64',
                'int32',
                'int64',
                'complex64',
                'complex128',
            ],
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            op_type,
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        )
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        helper = LayerHelper(op_type, **locals())
        if name is None:
            out = helper.create_variable_for_type_inference(dtype=x.dtype)
        else:
            out = helper.create_variable(
                name=name, dtype=x.dtype, persistable=False
            )
        helper.append_op(
            type="dot", inputs={'X': x, 'Y': y}, attrs={}, outputs={"Out": out}
1157
        )
1158
        return out
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def cov(x, rowvar=True, ddof=True, fweights=None, aweights=None, name=None):
    """
    Estimate the covariance matrix of the input variables, given data and weights.

    A covariance matrix is a square matrix, indicate the covariance of each pair variables in the input matrix.
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    For example, for an N-dimensional samples X=[x1,x2,…xN]T, then the covariance matrix
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    element Cij is the covariance of xi and xj. The element Cii is the variance of xi itself.

    Parameters:
        x(Tensor): A N-D(N<=2) Tensor containing multiple variables and observations. By default, each row of x represents a variable. Also see rowvar below.
        rowvar(Bool, optional): If rowvar is True (default), then each row represents a variable, with observations in the columns. Default: True
        ddof(Bool, optional): If ddof=True will return the unbiased estimate, and ddof=False will return the simple average. Default: True
        fweights(Tensor, optional): 1-D Tensor of integer frequency weights; The number of times each observation vector should be repeated. Default: None
        aweights(Tensor, optional): 1-D Tensor of observation vector weights. How important of the observation vector, larger data means this element is more important. Default: None
        name(str, optional): Name of the output. Default is None. It's used to print debug info for developers. Details: :ref:`api_guide_Name`

    Returns:
        Tensor: The covariance matrix Tensor of the variables.

    Examples:

    .. code-block:: python

        import paddle

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        xt = paddle.rand((3, 4))
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        paddle.linalg.cov(xt)

        '''
        Tensor(shape=[3, 3], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            [[0.07918842, 0.06127326, 0.01493049],
                [0.06127326, 0.06166256, 0.00302668],
                [0.01493049, 0.00302668, 0.01632146]])
        '''
    """
    op_type = 'cov'
    if len(x.shape) > 2 or len(x.shape) < 1:
        raise ValueError(
            "Input(x) only support N-D (1<=N<=2) tensor in cov, but received "
1200 1201
            "length of Input(input) is %s." % len(x.shape)
        )
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    check_variable_and_dtype(x, 'dtype', ['float32', 'float64'], 'cov')
    nx = x
    if len(x.shape) == 1:
        nx = x.reshape((1, -1))
    if not rowvar and nx.shape[0] != 1:
        nx = nx.t()
    w = None
    observation_num = nx.shape[1]
    if fweights is not None:
        w = fweights.astype(nx.dtype)
        if len(w.shape) > 1:
            raise ValueError(
                "Input(fweights) only support N-D (N<=1) tensor in cov, but received "
1215 1216
                "shape of Input(input) is %s." % len(fweights.shape)
            )
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        if fweights.shape[0] != observation_num:
            raise ValueError(
                "The number of Input(fweights) should equal to x's dim[1]: {}, but received "
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                "size of Input(fweights) is {}.".format(
                    observation_num, fweights.shape[0]
                )
            )
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        if fweights.min() < 0:
            raise ValueError(
                "The value of Input(fweights) cannot be negtive, but received "
1227 1228
                "min of Input(fweights) is {}.".format(fweights.min())
            )
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        if not paddle.all(fweights == paddle.round(fweights.astype('float64'))):
            raise ValueError("Input(fweights) must be integer ")

    if aweights is not None:
        aw = aweights.astype(nx.dtype)
        if len(aw.shape) > 1:
            raise ValueError(
                "Input(aweights) only support N-D (N<=1) tensor in cov, but received "
1237 1238 1239 1240 1241
                "length of Input(input) is %s." % len(aweights.shape)
            )
        check_variable_and_dtype(
            aweights, 'dtype', ['float32', 'float64'], 'cov'
        )
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        if aweights.shape[0] != observation_num:
            raise ValueError(
                "The number of Input(aweights) should equal to x's dim[1]: {}, but received "
1245 1246 1247 1248
                "size of Input(aweights) is {}.".format(
                    observation_num, aweights.shape[0]
                )
            )
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        if aweights.min() < 0:
            raise ValueError(
                "The value of Input(aweights) cannot be negtive, but received "
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                "min of Input(aweights) is {}.".format(aweights.min())
            )
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        if w is not None:
            w = w * aw
        else:
            w = aw

    w_sum = paddle.to_tensor(observation_num, dtype=nx.dtype)
    if fweights is not None or aweights is not None:
        w_sum = w.sum()
        if w_sum.item() == 0:
            raise ValueError("The sum of weights is zero, can't be normalized.")

    if w is not None:
        nx_w = nx * w
        avg = (nx_w).sum(axis=1) / w_sum
    else:
        avg = nx.sum(axis=1) / w_sum
        nx_w = nx

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    if w is not None and aweights is not None and ddof:
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        norm_factor = w_sum - (w * aweights).sum() / w_sum
    else:
        norm_factor = w_sum - ddof
    if norm_factor <= 0:
        norm_factor = paddle.to_tensor(0, dtype=nx.dtype)
    nx = nx - avg.unsqueeze(1)
    xxt = paddle.mm(nx, nx_w.t().conj())
    cov = paddle.divide(xxt, norm_factor).squeeze()
    return cov


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def t(input, name=None):
    """
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    Transpose <=2-D tensor.
    0-D and 1-D tensors are returned as it is and 2-D tensor is equal to
1288
    the paddle.transpose function which perm dimensions set 0 and 1.
1289

1290
    Args:
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        input (Tensor): The input Tensor. It is a N-D (N<=2) Tensor of data types float32, float64, int32, int64.
1292
        name(str, optional): The default value is None.  Normally there is no need for
1293 1294
            user to set this property.  For more information, please refer to :ref:`api_guide_Name`
    Returns:
1295
        Tensor: A transposed n-D Tensor, with data type being float16, float32, float64, int32, int64.
1296

1297
    Examples:
1298

1299 1300 1301
        .. code-block:: python
           :name: code-example
             import paddle
1302

1303
             # Example 1 (0-D tensor)
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             x = paddle.to_tensor([0.79])
             paddle.t(x) # [0.79]
1306

1307
             # Example 2 (1-D tensor)
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             x = paddle.to_tensor([0.79, 0.84, 0.32])
             paddle.t(x) # [0.79000002, 0.83999997, 0.31999999]
             paddle.t(x).shape # [3]
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             # Example 3 (2-D tensor)
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             x = paddle.to_tensor([[0.79, 0.84, 0.32],
                                  [0.64, 0.14, 0.57]])
             x.shape # [2, 3]
             paddle.t(x)
             # [[0.79000002, 0.63999999],
             #  [0.83999997, 0.14000000],
             #  [0.31999999, 0.56999999]]
             paddle.t(x).shape # [3, 2]
1321

1322 1323 1324 1325 1326
    """
    if len(input.shape) > 2:
        raise ValueError(
            "Input(input) only support N-D (N<=2) tensor, but received "
            "length of Input(input) is %s. Perhaps you can use paddle."
1327 1328
            "tensor.transpose() instead." % len(input.shape)
        )
1329
    if in_dynamic_mode():
1330
        if len(input.shape) <= 1:
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            return input
        # 2-D tensor
        perm = [1, 0]
1334
        out = _C_ops.transpose(input, perm)
1335
        return out
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    else:
        check_variable_and_dtype(
            input,
            'input',
            ['float16', 'float32', 'float64', 'int32', 'int64'],
            'transpose',
        )
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1344 1345 1346
        helper = LayerHelper('t', **locals())
        out = helper.create_variable_for_type_inference(input.dtype)
        input_shape = helper.create_variable_for_type_inference(input.dtype)
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        if len(input.shape) <= 1:
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            out = input
        else:
            helper.append_op(
                type='transpose2',
                inputs={'X': [input]},
                outputs={'Out': [out], 'XShape': [input_shape]},
                attrs={'axis': [1, 0]},
            )
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        return out

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def cross(x, y, axis=9, name=None):
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    """
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    Computes the cross product between two tensors along an axis.
1362

1363 1364
    Inputs must have the same shape, and the length of their axes should be equal to 3.
    If `axis` is not given, it defaults to the first axis found with the length 3.
1365

1366
    Args:
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        x (Tensor): The first input tensor, the data type is float16, float32, float64, int32, int64.
        y (Tensor): The second input tensor, the data type is float16, float32, float64, int32, int64.
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        axis (int, optional): The axis along which to compute the cross product. It defaults to be 9 which indicates using the first axis found with the length 3.
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        name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`.
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    Returns:
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        Tensor. A Tensor with same data type as `x`.
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    Examples:
        .. code-block:: python
1377

1378
            import paddle
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            x = paddle.to_tensor([[1.0, 1.0, 1.0],
                                  [2.0, 2.0, 2.0],
                                  [3.0, 3.0, 3.0]])
            y = paddle.to_tensor([[1.0, 1.0, 1.0],
                                  [1.0, 1.0, 1.0],
                                  [1.0, 1.0, 1.0]])
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            z1 = paddle.cross(x, y)
            # [[-1. -1. -1.]
            #  [ 2.  2.  2.]
            #  [-1. -1. -1.]]

            z2 = paddle.cross(x, y, axis=1)
            # [[0. 0. 0.]
            #  [0. 0. 0.]
            #  [0. 0. 0.]]
1396
    """
1397
    if in_dynamic_mode():
1398
        axis = K_DEFAULT_DIM if axis is None else axis
1399
        return _C_ops.cross(x, y, axis)
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    else:
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        check_variable_and_dtype(
            x,
            'x',
1404
            ['float16', 'uint16', 'float32', 'float64', "int32", "int64"],
1405 1406 1407 1408 1409
            'cross',
        )
        check_variable_and_dtype(
            y,
            'y',
1410
            ['float16', 'uint16', 'float32', 'float64', "int32", "int64"],
1411 1412
            'cross',
        )
1413 1414
        helper = LayerHelper("cross", **locals())
        out = helper.create_variable_for_type_inference(x.dtype)
1415
        attrs = {}
1416
        attrs['dim'] = axis
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        helper.append_op(
            type='cross',
            inputs={'X': x, 'Y': y},
            outputs={'Out': out},
            attrs=attrs,
        )
        return out
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def cholesky(x, upper=False, name=None):
1428
    r"""
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    Computes the Cholesky decomposition of one symmetric positive-definite
1430 1431
    matrix or batches of symmetric positive-definite matrice.

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    If `upper` is `True`, the decomposition has the form :math:`A = U^{T}U` ,
    and the returned matrix :math:`U` is upper-triangular. Otherwise, the
    decomposition has the form  :math:`A = LL^{T}` , and the returned matrix
    :math:`L` is lower-triangular.

    Args:
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        x (Tensor): The input tensor. Its shape should be `[*, M, M]`,
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            where * is zero or more batch dimensions, and matrices on the
            inner-most 2 dimensions all should be symmetric positive-definite.
            Its data type should be float32 or float64.
        upper (bool): The flag indicating whether to return upper or lower
            triangular matrices. Default: False.
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        name (str, optional): Name for the operation (optional, default is None).
            For more information, please refer to :ref:`api_guide_Name`.
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    Returns:
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        Tensor, A Tensor with same shape and data type as `x`. It represents
        triangular matrices generated by Cholesky decomposition.
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    Examples:
        .. code-block:: python

            import paddle

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            a = paddle.rand([3, 3], dtype="float32")
            a_t = paddle.transpose(a, [1, 0])
            x = paddle.matmul(a, a_t) + 1e-03

1460
            out = paddle.linalg.cholesky(x, upper=False)
1461
            print(out)
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    """
1463
    if in_dynamic_mode():
1464
        return _C_ops.cholesky(x, upper)
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    else:
        check_variable_and_dtype(x, 'dtype', ['float32', 'float64'], 'cholesky')
        check_type(upper, 'upper', bool, 'cholesky')
        helper = LayerHelper('cholesky', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
        helper.append_op(
            type='cholesky',
            inputs={'X': [x]},
            outputs={'Out': out},
            attrs={'upper': upper},
        )
        return out
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def matrix_rank(x, tol=None, hermitian=False, name=None):
    r"""
    Computes the rank of a matrix.

1483
    The rank of a matrix is the number of singular values that are greater than the specified `tol` threshold when hermitian=False,
1484
    or the number of eigenvalues in absolute value that are greater than the specified `tol` threshold when hermitian=True.
1485 1486

    Args:
1487 1488 1489 1490
        x (Tensor): The input tensor. Its shape should be `[..., m, n]`, where `...` is zero or more batch dimensions. If `x` is a batch
            of matrices then the output has the same batch dimensions. The data type of `x` should be float32 or float64.
        tol (float,Tensor,optional): the tolerance value. Default: None. If `tol` is not specified, and `sigma` is the largest
            singular value (or eigenvalues in absolute value), and `eps` is the epsilon value for the dtype of `x`, then `tol` is computed
1491
            with formula `tol=sigma * max(m,n) * eps`. Note that if `x` is a batch of matrices, `tol` is computed this way for every batch.
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        hermitian (bool,optional): indicates whether `x` is Hermitian. Default: False. When hermitian=True, `x` is assumed to be Hermitian,
            enabling a more efficient method for finding eigenvalues, but `x` is not checked inside the function. Instead, We just use
1494
            the lower triangular of the matrix to compute.
1495 1496 1497 1498
        name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Tensor: Rank of tensor x.
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1500 1501 1502 1503 1504 1505 1506 1507
    Examples:
        .. code-block:: python

            import paddle

            a = paddle.eye(10)
            b = paddle.linalg.matrix_rank(a)
            print(b)
1508
            # b = 10
1509 1510 1511 1512 1513 1514 1515

            c = paddle.ones(shape=[3, 4, 5, 5])
            d = paddle.linalg.matrix_rank(c, tol=0.01, hermitian=True)
            print(d)
            # d = [[1, 1, 1, 1],
            #      [1, 1, 1, 1],
            #      [1, 1, 1, 1]]
1516

1517
    """
1518
    if in_dynamic_mode():
1519 1520 1521 1522 1523 1524
        if isinstance(tol, Variable):
            if tol.dtype != x.dtype:
                tol_tensor = cast(tol, x.dtype)
            else:
                tol_tensor = tol
            use_default_tol = False
1525 1526 1527
            return _C_ops.matrix_rank_tol(
                x, tol_tensor, use_default_tol, hermitian
            )
1528

1529 1530 1531 1532 1533 1534
        if tol is None:
            tol_attr = 0.0
            use_default_tol = True
        else:
            tol_attr = float(tol)
            use_default_tol = False
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        return _C_ops.matrix_rank(x, tol_attr, use_default_tol, hermitian)
1536 1537 1538 1539 1540
    else:
        inputs = {}
        attrs = {}
        check_variable_and_dtype(x, 'x', ['float32', 'float64'], 'matrix_rank')
        inputs['X'] = x
1541
        if tol is None:
1542
            attrs['use_default_tol'] = True
1543
        elif isinstance(tol, Variable):
1544
            attrs['use_default_tol'] = False
1545
            if tol.dtype != x.dtype:
1546
                inputs['TolTensor'] = cast(tol, x.dtype)
1547
            else:
1548
                inputs['TolTensor'] = tol
1549
        else:
1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561
            check_type(tol, 'tol', float, 'matrix_rank')
            attrs['use_default_tol'] = False
            attrs['tol'] = tol
        check_type(hermitian, 'hermitian', bool, 'matrix_rank')
        attrs['hermitian'] = hermitian

        helper = LayerHelper('matrix_rank', **locals())
        out = helper.create_variable_for_type_inference(dtype='int32')
        helper.append_op(
            type='matrix_rank', inputs=inputs, outputs={'Out': out}, attrs=attrs
        )
        return out
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def bmm(x, y, name=None):
    """
    Applies batched matrix multiplication to two tensors.

    Both of the two input tensors must be three-dementional and share the same batch size.

    if x is a (b, m, k) tensor, y is a (b, k, n) tensor, the output will be a (b, m, n) tensor.

    Args:
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        x (Tensor): The input Tensor.
        y (Tensor): The input Tensor.
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        name(str|None): A name for this layer(optional). If set None, the layer
            will be named automatically.

    Returns:
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        Tensor: The product Tensor.
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    Examples:
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        .. code-block:: python

            import paddle
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            # In imperative mode:
            # size x: (2, 2, 3) and y: (2, 3, 2)
            x = paddle.to_tensor([[[1.0, 1.0, 1.0],
                                [2.0, 2.0, 2.0]],
                                [[3.0, 3.0, 3.0],
                                [4.0, 4.0, 4.0]]])
            y = paddle.to_tensor([[[1.0, 1.0],[2.0, 2.0],[3.0, 3.0]],
                                [[4.0, 4.0],[5.0, 5.0],[6.0, 6.0]]])
            out = paddle.bmm(x, y)
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            # Tensor(shape=[2, 2, 2], dtype=float32, place=Place(cpu), stop_gradient=True,
            #        [[[6. , 6. ],
            #          [12., 12.]],

            #         [[45., 45.],
            #          [60., 60.]]])
1601

1602
    """
1603
    if in_dynamic_mode():
1604
        return _C_ops.bmm(x, y)
1605
    else:
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        x_shape = x.shape
        y_shape = y.shape
        if not len(x_shape) == len(y_shape) == 3:
            raise ValueError(
                "x and y should be 3-dimensional. But received x's dimention: {}, y's dimention: {}".format(
                    x_shape, y_shape
                )
            )
1614
        if x_shape[2] != -1 and y_shape[1] != -1 and x_shape[2] != y_shape[1]:
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            raise ValueError(
                "x's width must be equal with y's height. But received x's shape: {}, y's shape: {}".format(
                    x_shape, y_shape
                )
            )
1620
        if x_shape[0] != -1 and y_shape[0] != -1 and x_shape[0] != y_shape[0]:
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            raise ValueError(
                "x's batch (shape[0]) must be equal with y's batch (shape[0]). But received x's shape: {}, y's shape: {}".format(
                    x_shape, y_shape
                )
            )
1626 1627 1628 1629 1630 1631
        helper = LayerHelper('bmm', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
        helper.append_op(
            type='bmm', inputs={'X': x, 'Y': y}, outputs={'Out': out}
        )
        return out
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1634
def histogram(input, bins=100, min=0, max=0, name=None):
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    """
1636
    Computes the histogram of a tensor. The elements are sorted into equal width bins between min and max.
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    If min and max are both zero, the minimum and maximum values of the data are used.

    Args:
1640
        input (Tensor): A Tensor(or LoDTensor) with shape :math:`[N_1, N_2,..., N_k]` . The data type of the input Tensor
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            should be float32, float64, int32, int64.
1642 1643 1644 1645
        bins (int, optional): number of histogram bins.
        min (int, optional): lower end of the range (inclusive).
        max (int, optional): upper end of the range (inclusive).
        name (str, optional): For details, please refer to :ref:`api_guide_Name`. Generally, no setting is required. Default: None.
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    Returns:
1648
        Tensor: data type is int64, shape is (nbins,).
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1650
    Examples:
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        .. code-block:: python
1652

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            import paddle
1654

1655
            inputs = paddle.to_tensor([1, 2, 1])
1656 1657
            result = paddle.histogram(inputs, bins=4, min=0, max=3)
            print(result) # [0, 2, 1, 0]
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    """
1659
    if in_dynamic_mode():
1660
        return _C_ops.histogram(input, bins, min, max)
1661 1662 1663 1664
    else:
        helper = LayerHelper('histogram', **locals())
        check_variable_and_dtype(
            input, 'X', ['int32', 'int64', 'float32', 'float64'], 'histogram'
1665
        )
1666 1667 1668 1669 1670 1671 1672 1673
        out = helper.create_variable_for_type_inference(VarDesc.VarType.INT64)
        helper.append_op(
            type='histogram',
            inputs={'X': input},
            outputs={'Out': out},
            attrs={'bins': bins, 'min': min, 'max': max},
        )
        return out
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def bincount(x, weights=None, minlength=0, name=None):
    """
1678
    Computes frequency of each value in the input tensor.
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    Args:
        x (Tensor): A Tensor with non-negative integer. Should be 1-D tensor.
        weights (Tensor, optional): Weight for each value in the input tensor. Should have the same shape as input. Default is None.
        minlength (int, optional): Minimum number of bins. Should be non-negative integer. Default is 0.
        name(str, optional): The default value is None.  Normally there is no need for user to set this
            property.  For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Tensor: The tensor of frequency.

    Examples:
        .. code-block:: python

            import paddle

            x = paddle.to_tensor([1, 2, 1, 4, 5])
            result1 = paddle.bincount(x)
            print(result1) # [0, 2, 1, 0, 1, 1]

            w = paddle.to_tensor([2.1, 0.4, 0.1, 0.5, 0.5])
            result2 = paddle.bincount(x, weights=w)
            print(result2) # [0., 2.19999981, 0.40000001, 0., 0.50000000, 0.50000000]
    """
    if x.dtype not in [paddle.int32, paddle.int64]:
        raise TypeError("Elements in Input(x) should all be integers")

1706
    if in_dynamic_mode():
1707
        return _C_ops.bincount(x, weights, minlength)
1708 1709
    else:
        helper = LayerHelper('bincount', **locals())
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1711
        check_variable_and_dtype(x, 'X', ['int32', 'int64'], 'bincount')
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        if weights is not None:
            check_variable_and_dtype(
                weights,
                'Weights',
                ['int32', 'int64', 'float32', 'float64'],
                'bincount',
            )
            out = helper.create_variable_for_type_inference(dtype=weights.dtype)
        else:
            out = helper.create_variable_for_type_inference(dtype=x.dtype)
        helper.append_op(
            type='bincount',
            inputs={'X': x, 'Weights': weights},
            outputs={'Out': out},
            attrs={'minlength': minlength},
1728
        )
1729
        return out
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def mv(x, vec, name=None):
    """
    Performs a matrix-vector product of the matrix x and the vector vec.

    Args:
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        x (Tensor): A tensor with shape :math:`[M, N]` , The data type of the input Tensor x
1738
            should be one of float32, float64.
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        vec (Tensor): A tensor with shape :math:`[N]` , The data type of the input Tensor x
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            should be one of float32, float64.
        name(str, optional): The default value is None.  Normally there is no need for user to set this
            property.  For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Tensor: The tensor which is producted by x and vec.

    Examples:
        .. code-block:: python

            # x: [M, N], vec: [N]
            # paddle.mv(x, vec)  # out: [M]

            import paddle

1755 1756
            x = paddle.to_tensor([[2, 1, 3], [3, 0, 1]]).astype("float64")
            vec = paddle.to_tensor([3, 5, 1]).astype("float64")
1757
            out = paddle.mv(x, vec)
1758 1759 1760
            print(out)
            # Tensor(shape=[2], dtype=float64, place=Place(cpu), stop_gradient=True,
            #        [14., 10.])
1761
    """
1762
    if in_dynamic_mode():
1763
        return _C_ops.mv(x, vec)
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    else:
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        def __check_input(x, vec):
            var_names = {'x': x, 'vec': vec}
            for name, val in var_names.items():
                check_variable_and_dtype(
                    val, name, ['float32', 'float64'], 'mv'
                )
            x_shape = list(x.shape)
            vec_shape = list(vec.shape)
            if len(x_shape) != 2:
                raise ValueError(
                    "x should be 2-dimensional. But received x's dimention: {}".format(
                        x_shape
1778
                    )
1779 1780 1781 1782 1783
                )
            if len(vec_shape) != 1:
                raise ValueError(
                    "vec should be 1-dimensional. But received vec's dimention: {}".format(
                        vec_shape
1784
                    )
1785
                )
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1787
        __check_input(x, vec)
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        helper = LayerHelper('mv', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
        helper.append_op(
            type='mv', inputs={'X': x, 'Vec': vec}, outputs={'Out': out}
        )
        return out
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1797
def det(x, name=None):
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    """
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    Calculates determinant value of a square matrix or batches of square matrices.
1801

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    Args:
1803
        x (Tensor): the input matrix of size `(n, n)` or the
1804 1805
            batch of matrices of size `(*, n, n)` where `*` is one or more
            batch dimensions.
1806 1807
        name(str, optional): Name of the output. Default is None. It's used
            to print debug info for developers. Details: :ref:`api_guide_Name`
1808

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    Returns:
1810
        Tensor, the determinant value of a square matrix or batches of square matrices.
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1812
    Examples:
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        .. code-block:: python

1815
            import paddle
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1817
            x =  paddle.randn([3,3,3])
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1819
            A = paddle.linalg.det(x)
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1821
            print(A)
1822

1823
            # [ 0.02547996,  2.52317095, -6.15900707])
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1825

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    """
1827
    if in_dynamic_mode():
1828
        return _C_ops.det(x)
1829
    else:
1830
        check_dtype(x.dtype, 'Input', ['float16', 'float32', 'float64'], 'det')
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        input_shape = list(x.shape)
        assert len(input_shape) >= 2, (
            "The x must be at least 2-dimensional, "
            "but received Input x's dimensional: %s.\n" % len(input_shape)
        )
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1838 1839
        assert (
            input_shape[-1] == input_shape[-2]
1840
        ), "Expect squared input," "but received {} by {} matrix.\n".format(
1841 1842 1843 1844 1845
            input_shape[-2],
            input_shape[-1],
        )
        helper = LayerHelper('determinant', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
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        helper.append_op(
            type='determinant', inputs={'Input': [x]}, outputs={'Out': [out]}
        )
        return out
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1853
def slogdet(x, name=None):
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    """
1855

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    Calculates the sign and natural logarithm of the absolute value of a square matrix's or batches square matrices' determinant.
1857
    The determinant can be computed with ``sign * exp`` (logabsdet)
1858

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    Supports input of float, double

    Note that for matrices that have zero determinant, this returns ``(0, -inf)``
1862

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    Args:
        x (Tensor): the batch of matrices of size :math:`(*, n, n)`
            where math:`*` is one or more batch dimensions.

    Returns:
1868
        y (Tensor), A tensor containing the sign of the determinant and the natural logarithm
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        of the absolute value of determinant, respectively.

1871
    Examples:
1872
        .. code-block:: python
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1874
            import paddle
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1876
            x =  paddle.randn([3,3,3])
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1878
            A = paddle.linalg.slogdet(x)
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1880
            print(A)
1881

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            # [[ 1.        ,  1.        , -1.        ],
            # [-0.98610914, -0.43010661, -0.10872950]])
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    """
1886
    if in_dynamic_mode():
1887
        return _C_ops.slogdet(x)
1888 1889
    else:
        check_dtype(x.dtype, 'Input', ['float32', 'float64'], 'slogdet')
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1891 1892 1893 1894 1895
        input_shape = list(x.shape)
        assert len(input_shape) >= 2, (
            "The x must be at least 2-dimensional, "
            "but received Input x's dimensional: %s.\n" % len(input_shape)
        )
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        assert (
            input_shape[-1] == input_shape[-2]
1899
        ), "Expect squared input," "but received {} by {} matrix.\n".format(
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            input_shape[-2],
            input_shape[-1],
        )
        helper = LayerHelper('slogdeterminant', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
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        helper.append_op(
            type='slogdeterminant',
            inputs={'Input': [x]},
            outputs={'Out': [out]},
        )
        return out
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1914 1915
def svd(x, full_matrices=False, name=None):
    r"""
1916 1917 1918 1919 1920
    Computes the singular value decomposition of one matrix or a batch of regular matrices.

    Let :math:`X` be the input matrix or a batch of input matrices, the output should satisfies:

    .. math::
1921 1922
        X = U * diag(S) * VT

1923 1924
    Args:
        x (Tensor): The input tensor. Its shape should be `[..., N, M]`,
1925
            where `...` is zero or more batch dimensions. N and M can be arbitraty
1926 1927
            positive number. Note that if x is sigular matrices, the grad is numerical
            instable. The data type of x should be float32 or float64.
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        full_matrices (bool, optional): A flag to control the behavor of svd.
1929
            If full_matrices = True, svd op will compute full U and V matrics,
1930
            which means shape of U is `[..., N, N]`, shape of V is `[..., M, M]`. K = min(M, N).
1931
            If full_matrices = False, svd op will use a economic method to store U and V.
1932
            which means shape of U is `[..., N, K]`, shape of V is `[..., M, K]`. K = min(M, N).
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            Default value is False.
1934
        name (str, optional): Name for the operation (optional, default is None).
1935
            For more information, please refer to :ref:`api_guide_Name`.
1936 1937

    Returns:
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        - U (Tensor), is the singular value decomposition result U.
        - S (Tensor), is the singular value decomposition result S.
        - VH (Tensor), VH is the conjugate transpose of V, which is the singular value decomposition result V.

        Tuple of 3 tensors(U, S, VH): VH is the conjugate transpose of V. S is the singlar value vectors of matrics with shape `[..., K]`
1943

1944 1945 1946 1947
    Examples:
        .. code-block:: python

            import paddle
1948 1949 1950

            x = paddle.to_tensor([[1.0, 2.0], [1.0, 3.0], [4.0, 6.0]]).astype('float64')
            x = x.reshape([3, 2])
1951
            u, s, vh = paddle.linalg.svd(x)
1952 1953 1954 1955 1956
            print (u)
            #U = [[ 0.27364809, -0.21695147  ],
            #      [ 0.37892198, -0.87112408 ],
            #      [ 0.8840446 ,  0.44053933 ]]

1957
            print (s)
1958
            #S = [8.14753743, 0.78589688]
1959
            print (vh)
1960 1961
            #VT= [[ 0.51411221,  0.85772294],
            #     [ 0.85772294, -0.51411221]]
1962

1963
            # one can verify : U * S * VT == X
1964
            #                  U * UH == I
1965
            #                  V * VH == I
1966
    """
1967

1968
    if in_dynamic_mode():
1969
        return _C_ops.svd(x, full_matrices)
1970 1971 1972 1973 1974 1975 1976
    else:
        check_variable_and_dtype(x, 'dtype', ['float32', 'float64'], 'svd')
        check_type(full_matrices, 'full_matrices', bool, 'svd')
        helper = LayerHelper('svd', **locals())
        u = helper.create_variable_for_type_inference(dtype=x.dtype)
        vh = helper.create_variable_for_type_inference(dtype=x.dtype)
        s = helper.create_variable_for_type_inference(dtype=x.dtype)
1977
        attrs = {}
1978 1979 1980 1981 1982 1983 1984 1985
        attrs['full_matrices'] = full_matrices
        helper.append_op(
            type='svd',
            inputs={'X': [x]},
            outputs={'U': u, 'VH': vh, 'S': s},
            attrs=attrs,
        )
        return u, s, vh
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def pca_lowrank(x, q=None, center=True, niter=2, name=None):
    r"""
    Performs linear Principal Component Analysis (PCA) on a low-rank matrix or batches of such matrices.

    Let :math:`X` be the input matrix or a batch of input matrices, the output should satisfies:

    .. math::
        X = U * diag(S) * V^{T}

    Args:
        x (Tensor): The input tensor. Its shape should be `[..., N, M]`,
            where `...` is zero or more batch dimensions. N and M can be arbitraty
            positive number. The data type of x should be float32 or float64.
        q (int, optional): a slightly overestimated rank of :math:`X`.
            Default value is :math:`q=min(6,N,M)`.
        center (bool, optional): if True, center the input tensor.
            Default value is True.
        name (str, optional): Name for the operation (optional, default is None).
            For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        - Tensor U, is N x q matrix.
        - Tensor S, is a vector with length q.
        - Tensor V, is M x q matrix.

        tuple (U, S, V): which is the nearly optimal approximation of a singular value decomposition of a centered matrix :math:`X`.

    Examples:
        .. code-block:: python

            import paddle

            x = paddle.randn((5, 5), dtype='float64')
            U, S, V = paddle.linalg.pca_lowrank(x)
            print(U)
            # Tensor(shape=[5, 5], dtype=float64, place=Place(gpu:0), stop_gradient=True,
            #        [[ 0.41057070,  0.40364287,  0.59099574, -0.34529432,  0.44721360],
            #         [-0.30243321,  0.55670611, -0.15025419,  0.61321785,  0.44721360],
            #         [ 0.57427340, -0.15936327, -0.66414981, -0.06097905,  0.44721360],
            #         [-0.63897516, -0.09968973, -0.17298615, -0.59316819,  0.44721360],
            #         [-0.04343573, -0.70129598,  0.39639442,  0.38622370,  0.44721360]])

            print(S)
            # Tensor(shape=[5], dtype=float64, place=Place(gpu:0), stop_gradient=True,
            #        [3.33724265, 2.57573259, 1.69479048, 0.68069312, 0.00000000])

            print(V)
            # Tensor(shape=[5, 5], dtype=float64, place=Place(gpu:0), stop_gradient=True,
            #        [[ 0.09800724, -0.32627008, -0.23593953,  0.81840445,  0.39810690],
            #         [-0.60100303,  0.63741176, -0.01953663,  0.09023999,  0.47326173],
            #         [ 0.25073864, -0.21305240, -0.32662950, -0.54786156,  0.69634740],
            #         [ 0.33057205,  0.48282641, -0.75998527,  0.06744040, -0.27472705],
            #         [ 0.67604895,  0.45688227,  0.50959437,  0.13179682,  0.23908071]])
    """

    def conjugate(x):
        if x.is_complex():
            return x.conj()
        return x

    def transpose(x):
        shape = x.shape
        perm = list(range(0, len(shape)))
        perm = perm[:-2] + [perm[-1]] + [perm[-2]]
        return paddle.transpose(x, perm)

    def transjugate(x):
        return conjugate(transpose(x))

    def get_approximate_basis(x, q, niter=2, M=None):
        niter = 2 if niter is None else niter
        m, n = x.shape[-2:]
        qr = paddle.linalg.qr

        R = paddle.randn((n, q), dtype=x.dtype)

        A_t = transpose(x)
        A_H = conjugate(A_t)
        if M is None:
            Q = qr(paddle.matmul(x, R))[0]
            for i in range(niter):
                Q = qr(paddle.matmul(A_H, Q))[0]
                Q = qr(paddle.matmul(x, Q))[0]
        else:
            M_H = transjugate(M)
            Q = qr(paddle.matmul(x, R) - paddle.matmul(M, R))[0]
            for i in range(niter):
                Q = qr(paddle.matmul(A_H, Q) - paddle.matmul(M_H, Q))[0]
                Q = qr(paddle.matmul(x, Q) - paddle.matmul(M, Q))[0]

        return Q

    def svd_lowrank(x, q=6, niter=2, M=None):
        q = 6 if q is None else q
        m, n = x.shape[-2:]
        if M is None:
            M_t = None
        else:
            M_t = transpose(M)
        A_t = transpose(x)

        if m < n or n > q:
            Q = get_approximate_basis(A_t, q, niter=niter, M=M_t)
            Q_c = conjugate(Q)
            if M is None:
                B_t = paddle.matmul(x, Q_c)
            else:
                B_t = paddle.matmul(x, Q_c) - paddle.matmul(M, Q_c)
            assert B_t.shape[-2] == m, (B_t.shape, m)
            assert B_t.shape[-1] == q, (B_t.shape, q)
            assert B_t.shape[-1] <= B_t.shape[-2], B_t.shape
            U, S, Vh = paddle.linalg.svd(B_t, full_matrices=False)
            V = transjugate(Vh)
            V = Q.matmul(V)
        else:
            Q = get_approximate_basis(x, q, niter=niter, M=M)
            Q_c = conjugate(Q)
            if M is None:
                B = paddle.matmul(A_t, Q_c)
            else:
                B = paddle.matmul(A_t, Q_c) - paddle.matmul(M_t, Q_c)
            B_t = transpose(B)
            assert B_t.shape[-2] == q, (B_t.shape, q)
            assert B_t.shape[-1] == n, (B_t.shape, n)
            assert B_t.shape[-1] <= B_t.shape[-2], B_t.shape
            U, S, Vh = paddle.linalg.svd(B_t, full_matrices=False)
            V = transjugate(Vh)
            U = Q.matmul(U)

        return U, S, V

    if not paddle.is_tensor(x):
        raise ValueError(f'Input must be tensor, but got {type(x)}')

    (m, n) = x.shape[-2:]

    if q is None:
        q = min(6, m, n)
    elif not (q >= 0 and q <= min(m, n)):
        raise ValueError(
            'q(={}) must be non-negative integer'
            ' and not greater than min(m, n)={}'.format(q, min(m, n))
        )
    if not (niter >= 0):
        raise ValueError(f'niter(={niter}) must be non-negative integer')

    if not center:
        return svd_lowrank(x, q, niter=niter, M=None)

    C = x.mean(axis=-2, keepdim=True)
    return svd_lowrank(x - C, q, niter=niter, M=None)


2141 2142
def matrix_power(x, n, name=None):
    r"""
2143

2144
    Computes the n-th power of a square matrix or a batch of square matrices.
2145

2146 2147 2148 2149 2150
    Let :math:`X` be a sqaure matrix or a batch of square matrices, :math:`n` be
    an exponent, the equation should be:

    .. math::
        Out = X ^ {n}
2151

2152 2153
    Specifically,

2154
    - If `n > 0`, it returns the matrix or a batch of matrices raised to the power of `n`.
2155

2156 2157
    - If `n = 0`, it returns the identity matrix or a batch of identity matrices.

2158
    - If `n < 0`, it returns the inverse of each matrix (if invertible) raised to the power of `abs(n)`.
2159 2160 2161 2162 2163 2164

    Args:
        x (Tensor): A square matrix or a batch of square matrices to be raised
            to power `n`. Its shape should be `[*, M, M]`, where `*` is zero or
            more batch dimensions. Its data type should be float32 or float64.
        n (int): The exponent. It can be any positive, negative integer or zero.
2165
        name (str, optional): Name for the operation (optional, default is None).
2166 2167 2168
            For more information, please refer to :ref:`api_guide_Name`.

    Returns:
2169 2170
        - Tensor, The n-th power of the matrix (or the batch of matrices) `x`. Its
          data type should be the same as that of `x`.
2171 2172 2173 2174 2175 2176 2177 2178 2179

    Examples:
        .. code-block:: python

            import paddle

            x = paddle.to_tensor([[1, 2, 3],
                                  [1, 4, 9],
                                  [1, 8, 27]], dtype='float64')
2180
            print(paddle.linalg.matrix_power(x, 2))
2181 2182 2183 2184
            # [[6.  , 34. , 102.],
            #  [14. , 90. , 282.],
            #  [36. , 250., 804.]]

2185
            print(paddle.linalg.matrix_power(x, 0))
2186 2187 2188 2189
            # [[1., 0., 0.],
            #  [0., 1., 0.],
            #  [0., 0., 1.]]

2190
            print(paddle.linalg.matrix_power(x, -2))
2191 2192 2193 2194
            # [[ 12.91666667, -12.75000000,  2.83333333 ],
            #  [-7.66666667 ,  8.         , -1.83333333 ],
            #  [ 1.80555556 , -1.91666667 ,  0.44444444 ]]
    """
2195
    if in_dynamic_mode():
2196
        return _C_ops.matrix_power(x, n)
2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210
    else:
        check_variable_and_dtype(
            x, 'dtype', ['float32', 'float64'], 'matrix_power'
        )
        check_type(n, 'n', int, 'matrix_power')
        helper = LayerHelper('matrix_power', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
        helper.append_op(
            type='matrix_power',
            inputs={'X': x},
            outputs={'Out': out},
            attrs={'n': n},
        )
        return out
2211 2212


2213 2214 2215 2216 2217 2218 2219
def qr(x, mode="reduced", name=None):
    r"""
    Computes the QR decomposition of one matrix or batches of matrice (backward is unsupported now).

    Args:
        x (Tensor): The input tensor. Its shape should be `[..., M, N]`,
            where ... is zero or more batch dimensions. M and N can be arbitrary
2220 2221
            positive number. The data type of x should be float32 or float64.
        mode (str, optional): A flag to control the behavior of qr, the default is "reduced".
2222
            Suppose x's shape is `[..., M, N]` and denoting `K = min(M, N)`:
2223
            If mode = "reduced", qr op will return reduced Q and R matrices,
2224
            which means Q's shape is `[..., M, K]` and R's shape is `[..., K, N]`.
2225
            If mode = "complete", qr op will return complete Q and R matrices,
2226 2227 2228 2229 2230
            which means Q's shape is `[..., M, M]` and R's shape is `[..., M, N]`.
            If mode = "r", qr op will only return reduced R matrix, which means
            R's shape is `[..., K, N]`.
        name (str, optional): Name for the operation (optional, default is None).
            For more information, please refer to :ref:`api_guide_Name`.
2231

2232
    Returns:
2233
        If mode = "reduced" or mode = "complete", qr will return a two tensor-tuple, which represents Q and R.
2234
        If mode = "r", qr will return a tensor which represents R.
2235 2236

    Examples:
2237 2238
        .. code-block:: python

2239
            import paddle
2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251

            x = paddle.to_tensor([[1.0, 2.0], [3.0, 4.0], [5.0, 6.0]]).astype('float64')
            q, r = paddle.linalg.qr(x)
            print (q)
            print (r)

            # Q = [[-0.16903085,  0.89708523],
            #      [-0.50709255,  0.27602622],
            #      [-0.84515425, -0.34503278]])

            # R = [[-5.91607978, -7.43735744],
            #      [ 0.        ,  0.82807867]])
2252 2253

            # one can verify : X = Q * R ;
2254
    """
2255
    if in_dynamic_mode():
2256
        q, r = _C_ops.qr(x, mode)
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        if mode == "r":
            return r
        else:
            return q, r
2261 2262 2263 2264 2265 2266
    else:
        check_variable_and_dtype(x, 'dtype', ['float32', 'float64'], 'qr')
        check_type(mode, 'mode', str, 'qr')
        helper = LayerHelper('qr', **locals())
        q = helper.create_variable_for_type_inference(dtype=x.dtype)
        r = helper.create_variable_for_type_inference(dtype=x.dtype)
2267
        attrs = {}
2268 2269 2270 2271
        attrs['mode'] = mode
        helper.append_op(
            type='qr', inputs={'X': [x]}, outputs={'Q': q, 'R': r}, attrs=attrs
        )
2272 2273 2274 2275 2276 2277
        if mode == "r":
            return r
        else:
            return q, r


2278 2279
def lu(x, pivot=True, get_infos=False, name=None):
    r"""
2280
    Computes the LU factorization of an N-D(N>=2) matrix x.
2281

2282
    Returns the LU factorization(inplace x) and Pivots. low triangular matrix L and
2283 2284 2285 2286
    upper triangular matrix U are combined to a single LU matrix.

    Pivoting is done if pivot is set to True.
    P mat can be get by pivots:
2287 2288

    .. code-block:: text
2289

2290 2291 2292 2293
        ones = eye(rows) #eye matrix of rank rows
        for i in range(cols):
            swap(ones[i], ones[pivots[i]])
        return ones
2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304

    Args:

        X (Tensor): the tensor to factor of N-dimensions(N>=2).

        pivot (bool, optional): controls whether pivoting is done. Default: True.

        get_infos (bool, optional): if set to True, returns an info IntTensor. Default: False.

        name (str, optional): Name for the operation (optional, default is None).
            For more information, please refer to :ref:`api_guide_Name`.
2305

2306
    Returns:
2307
        factorization (Tensor), LU matrix, the factorization of input X.
2308

2309 2310 2311
        pivots (IntTensor), the pivots of size(∗(N-2), min(m,n)). `pivots` stores all the
        intermediate transpositions of rows. The final permutation `perm` could be
        reconstructed by this, details refer to upper example.
2312

2313 2314 2315
        infos (IntTensor, optional), if `get_infos` is `True`, this is a tensor of size (∗(N-2))
        where non-zero values indicate whether factorization for the matrix or each minibatch
        has succeeded or failed.
2316

2317 2318

    Examples:
2319 2320
        .. code-block:: python

2321
            import paddle
2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336

            x = paddle.to_tensor([[1.0, 2.0], [3.0, 4.0], [5.0, 6.0]]).astype('float64')
            lu,p,info = paddle.linalg.lu(x, get_infos=True)

            # >>> lu:
            # Tensor(shape=[3, 2], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            #    [[5.        , 6.        ],
            #        [0.20000000, 0.80000000],
            #        [0.60000000, 0.50000000]])
            # >>> p
            # Tensor(shape=[2], dtype=int32, place=CUDAPlace(0), stop_gradient=True,
            #    [3, 3])
            # >>> info
            # Tensor(shape=[], dtype=int32, place=CUDAPlace(0), stop_gradient=True,
            #    0)
2337

2338 2339 2340 2341 2342 2343
            P,L,U = paddle.linalg.lu_unpack(lu,p)

            # >>> P
            # (Tensor(shape=[3, 3], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            # [[0., 1., 0.],
            # [0., 0., 1.],
2344
            # [1., 0., 0.]]),
2345 2346 2347 2348
            # >>> L
            # Tensor(shape=[3, 2], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            # [[1.        , 0.        ],
            # [0.20000000, 1.        ],
2349
            # [0.60000000, 0.50000000]]),
2350 2351 2352 2353 2354
            # >>> U
            # Tensor(shape=[2, 2], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            # [[5.        , 6.        ],
            # [0.        , 0.80000000]]))

2355 2356

            # one can verify : X = P @ L @ U ;
2357
    """
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2358

2359
    if in_dynamic_mode():
2360
        lu, p, info = _C_ops.lu(x, pivot)
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    else:
        check_variable_and_dtype(x, 'dtype', ['float32', 'float64'], 'lu')
        helper = LayerHelper('lu', **locals())
        lu = helper.create_variable_for_type_inference(dtype=x.dtype)
        p = helper.create_variable_for_type_inference(dtype='int')
        info = helper.create_variable_for_type_inference(dtype='int')
2367
        attrs = {}
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        attrs['pivot'] = pivot
2369 2370 2371 2372 2373 2374
        helper.append_op(
            type='lu',
            inputs={'X': x},
            outputs={'Out': lu, 'Pivots': p, 'Infos': info},
            attrs=attrs,
        )
2375 2376 2377 2378 2379 2380 2381 2382
    if get_infos:
        return lu, p, info
    else:
        return lu, p


def lu_unpack(x, y, unpack_ludata=True, unpack_pivots=True, name=None):
    r"""
2383
    Unpack L U and P to single matrix tensor .
2384 2385 2386
    unpack L and U matrix from LU, unpack permutation matrix P from Pivtos .

    P mat can be get by pivots:
2387 2388

    .. code-block:: text
2389

2390 2391 2392
        ones = eye(rows) #eye matrix of rank rows
        for i in range(cols):
            swap(ones[i], ones[pivots[i]])
2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405


    Args:
        x (Tensor): The LU tensor get from paddle.linalg.lu, which is combined by L and U.

        y (Tensor): Pivots get from paddle.linalg.lu.

        unpack_ludata (bool,optional): whether to unpack L and U from x. Default: True.

        unpack_pivots (bool, optional): whether to unpack permutation matrix P from Pivtos. Default: True.

        name (str, optional): Name for the operation (optional, default is None).
            For more information, please refer to :ref:`api_guide_Name`.
2406

2407
    Returns:
2408
        P (Tensor), Permutation matrix P of lu factorization.
2409

2410
        L (Tensor), The lower triangular matrix tensor of lu factorization.
2411

2412
        U (Tensor), The upper triangular matrix tensor of lu factorization.
2413

2414 2415

    Examples:
2416 2417
        .. code-block:: python

2418
            import paddle
2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433

            x = paddle.to_tensor([[1.0, 2.0], [3.0, 4.0], [5.0, 6.0]]).astype('float64')
            lu,p,info = paddle.linalg.lu(x, get_infos=True)

            # >>> lu:
            # Tensor(shape=[3, 2], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            #    [[5.        , 6.        ],
            #        [0.20000000, 0.80000000],
            #        [0.60000000, 0.50000000]])
            # >>> p
            # Tensor(shape=[2], dtype=int32, place=CUDAPlace(0), stop_gradient=True,
            #    [3, 3])
            # >>> info
            # Tensor(shape=[], dtype=int32, place=CUDAPlace(0), stop_gradient=True,
            #    0)
2434

2435 2436 2437 2438 2439 2440
            P,L,U = paddle.linalg.lu_unpack(lu,p)

            # >>> P
            # (Tensor(shape=[3, 3], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            # [[0., 1., 0.],
            # [0., 0., 1.],
2441
            # [1., 0., 0.]]),
2442 2443 2444 2445
            # >>> L
            # Tensor(shape=[3, 2], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            # [[1.        , 0.        ],
            # [0.20000000, 1.        ],
2446
            # [0.60000000, 0.50000000]]),
2447 2448 2449 2450 2451
            # >>> U
            # Tensor(shape=[2, 2], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            # [[5.        , 6.        ],
            # [0.        , 0.80000000]]))

2452
            # one can verify : X = P @ L @ U ;
2453
    """
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    if x.ndim < 2:
        raise ValueError(
            f"The shape of x should be (*, M, N), but received ndim is [{x.ndim} < 2]"
        )
    if y.ndim < 1:
        raise ValueError(
            f"The shape of Pivots should be (*, K), but received ndim is [{y.ndim} < 1]"
        )
2462
    if in_dynamic_mode():
2463
        P, L, U = _C_ops.lu_unpack(x, y, unpack_ludata, unpack_pivots)
2464
        return P, L, U
2465 2466 2467
    else:
        check_variable_and_dtype(
            x, 'dtype', ['float32', 'float64'], 'lu_unpack'
2468
        )
2469 2470 2471 2472
        helper = LayerHelper('lu_unpack', **locals())
        p = helper.create_variable_for_type_inference(dtype=x.dtype)
        l = helper.create_variable_for_type_inference(dtype=x.dtype)
        u = helper.create_variable_for_type_inference(dtype=x.dtype)
2473

2474
        attrs = {}
2475 2476 2477 2478 2479 2480 2481 2482 2483
        attrs['unpack_ludata'] = unpack_ludata
        attrs['unpack_pivots'] = unpack_pivots
        helper.append_op(
            type='lu_unpack',
            inputs={'X': x, 'Pivots': y},
            outputs={'Pmat': p, 'L': l, 'U': u},
            attrs=attrs,
        )
        return p, l, u
2484 2485


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2486 2487
def eig(x, name=None):
    """
2488
    Performs the eigenvalue decomposition of a square matrix or a batch of square matrices.
L
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2489

2490 2491 2492 2493 2494 2495
    Note:
        - If the matrix is a Hermitian or a real symmetric matrix, please use :ref:`paddle.linalg.eigh` instead, which is much faster.
        - If only eigenvalues is needed, please use :ref:`paddle.linalg.eigvals` instead.
        - If the matrix is of any shape, please use :ref:`paddle.linalg.svd`.
        - This API is only supported on CPU device.
        - The output datatype is always complex for both real and complex input.
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2496 2497 2498 2499

    Args:
        x (Tensor): A tensor with shape math:`[*, N, N]`, The data type of the x should be one of ``float32``,
            ``float64``, ``compplex64`` or ``complex128``.
2500
        name (str, optional): The default value is `None`. Normally there is no need for user to set
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2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513
            this property. For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Eigenvalues(Tensors): A tensor with shape math:`[*, N]` refers to the eigen values.
        Eigenvectors(Tensors): A tensor with shape math:`[*, N, N]` refers to the eigen vectors.

    Examples:
        .. code-block:: python

            import paddle

            paddle.device.set_device("cpu")

2514
            x = paddle.to_tensor([[1.6707249, 7.2249975, 6.5045543],
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2515
                               [9.956216,  8.749598,  6.066444 ],
2516
                               [4.4251957, 1.7983172, 0.370647 ]])
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2517
            w, v = paddle.linalg.eig(x)
2518
            print(v)
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2519 2520 2521 2522 2523 2524 2525 2526
            # Tensor(shape=[3, 3], dtype=complex128, place=CPUPlace, stop_gradient=False,
            #       [[(-0.5061363550800655+0j) , (-0.7971760990842826+0j) ,
            #         (0.18518077798279986+0j)],
            #        [(-0.8308237755993192+0j) ,  (0.3463813401919749+0j) ,
            #         (-0.6837005269141947+0j) ],
            #        [(-0.23142567697893396+0j),  (0.4944999840400175+0j) ,
            #         (0.7058765252952796+0j) ]])

2527
            print(w)
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2528 2529 2530 2531
            # Tensor(shape=[3], dtype=complex128, place=CPUPlace, stop_gradient=False,
            #       [ (16.50471283351188+0j)  , (-5.5034820550763515+0j) ,
            #         (-0.21026087843552282+0j)])
    """
2532

2533
    if in_dynamic_mode():
2534
        return _C_ops.eig(x)
2535 2536 2537 2538 2539
    else:
        check_variable_and_dtype(
            x, 'X', ['float32', 'float64', 'complex64', 'complex128'], 'eig'
        )
        helper = LayerHelper('eig', **locals())
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2540

2541 2542
        w = helper.create_variable_for_type_inference(x.dtype)
        v = helper.create_variable_for_type_inference(x.dtype)
L
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2543

2544 2545 2546
        inputs = {'X': x}
        outputs = {'Eigenvalues': w, 'Eigenvectors': v}
        helper.append_op(type='eig', inputs=inputs, outputs=outputs)
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2547

2548
        return w, v
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2549 2550


2551 2552 2553
def eigvals(x, name=None):
    """
    Compute the eigenvalues of one or more general matrices.
2554 2555 2556

    Warning:
        The gradient kernel of this operator does not yet developed.
2557 2558 2559 2560
        If you need back propagation through this operator, please replace it with paddle.linalg.eig.

    Args:
        x (Tensor): A square matrix or a batch of square matrices whose eigenvalues will be computed.
2561
            Its shape should be `[*, M, M]`, where `*` is zero or more batch dimensions.
2562
            Its data type should be float32, float64, complex64, or complex128.
2563
        name (str, optional): Name for the operation (optional, default is None).
2564
            For more information, please refer to :ref:`api_guide_Name`.
2565

2566
    Returns:
2567 2568
        Tensor, A tensor containing the unsorted eigenvalues which has the same batch
        dimensions with `x`. The eigenvalues are complex-valued even when `x` is real.
2569 2570 2571 2572 2573

    Examples:
        .. code-block:: python

            import paddle
2574

2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589
            paddle.set_device("cpu")
            paddle.seed(1234)

            x = paddle.rand(shape=[3, 3], dtype='float64')
            # [[0.02773777, 0.93004224, 0.06911496],
            #  [0.24831591, 0.45733623, 0.07717843],
            #  [0.48016702, 0.14235102, 0.42620817]])

            print(paddle.linalg.eigvals(x))
            # [(-0.27078833542132674+0j), (0.29962280156230725+0j), (0.8824477020120244+0j)] #complex128
    """

    x_shape = list(x.shape)
    if len(x_shape) < 2:
        raise ValueError(
2590 2591 2592 2593
            "The dimension of Input(x) should be at least 2, but received x's dimention = {}, x's shape = {}".format(
                len(x_shape), x_shape
            )
        )
2594 2595 2596

    if x_shape[-1] != x_shape[-2]:
        raise ValueError(
2597 2598 2599 2600
            "The last two dimensions of Input(x) should be equal, but received x's shape = {}".format(
                x_shape
            )
        )
2601

2602
    if in_dynamic_mode():
2603
        return _C_ops.eigvals(x)
2604
    else:
2605 2606 2607 2608 2609 2610
        check_variable_and_dtype(
            x,
            'dtype',
            ['float32', 'float64', 'complex64', 'complex128'],
            'eigvals',
        )
2611 2612 2613 2614
        helper = LayerHelper('eigvals', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
        helper.append_op(type='eigvals', inputs={'X': x}, outputs={'Out': out})
        return out
2615 2616


2617 2618 2619 2620
def multi_dot(x, name=None):
    """
    Multi_dot is an operator that calculates multiple matrix multiplications.

2621
    Supports inputs of float16(only GPU support), float32 and float64 dtypes. This function does not
2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657
    support batched inputs.

    The input tensor in [x] must be 2-D except for the first and last can be 1-D.
    If the first tensor is a 1-D vector of shape(n, ) it is treated as row vector
    of shape(1, n), similarly if the last tensor is a 1D vector of shape(n, ), it
    is treated as a column vector of shape(n, 1).

    If the first and last tensor are 2-D matrix, then the output is also 2-D matrix,
    otherwise the output is a 1-D vector.

    Multi_dot will select the lowest cost multiplication order for calculation. The
    cost of multiplying two matrices with shapes (a, b) and (b, c) is a * b * c.
    Given matrices A, B, C with shapes (20, 5), (5, 100), (100, 10) respectively,
    we can calculate the cost of different multiplication orders as follows:
    - Cost((AB)C) = 20x5x100 + 20x100x10 = 30000
    - Cost(A(BC)) = 5x100x10 + 20x5x10 = 6000

    In this case, multiplying B and C first, then multiply A, which is 5 times faster
    than sequential calculation.

    Args:
        x ([Tensor]): The input tensors which is a list Tensor.
        name(str|None): A name for this layer(optional). If set None, the layer
            will be named automatically.

    Returns:
        Tensor: The output Tensor.


    Examples:

    .. code-block:: python

        import paddle

        # A * B
2658 2659
        A = paddle.rand([3, 4])
        B = paddle.rand([4, 5])
2660
        out = paddle.linalg.multi_dot([A, B])
2661
        print(out.shape)
2662 2663 2664
        # [3, 5]

        # A * B * C
2665 2666 2667
        A = paddle.rand([10, 5])
        B = paddle.rand([5, 8])
        C = paddle.rand([8, 7])
2668
        out = paddle.linalg.multi_dot([A, B, C])
2669
        print(out.shape)
2670 2671 2672
        # [10, 7]

    """
2673
    if in_dynamic_mode():
2674
        return _C_ops.multi_dot(x)
2675 2676 2677 2678 2679 2680
    else:
        check_type(x, 'x', (list, tuple), 'multi_dot')
        for id, item in enumerate(x):
            check_variable_and_dtype(
                item,
                'x[' + str(id) + ']',
2681
                ['float16', 'float32', 'float64', 'uint16'],
2682 2683 2684 2685 2686 2687
                'multi_dot',
            )
            if item.dtype != x[0].dtype:
                raise TypeError(
                    "All the Tensors in the input must have the same data type."
                )
2688

2689 2690 2691 2692 2693
        helper = LayerHelper('multi_dot', **locals())
        dtype = helper.input_dtype(input_param_name='x')
        out = helper.create_variable_for_type_inference(dtype)
        helper.append_op(
            type='multi_dot', inputs={"X": x}, outputs={"Out": out}
2694
        )
2695
        return out
2696 2697 2698 2699


def eigh(x, UPLO='L', name=None):
    """
2700
    Compute the eigenvalues and eigenvectors of a
2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711
    complex Hermitian (conjugate symmetric) or a real symmetric matrix.

    Args:
        x (Tensor): A tensor with shape :math:`[*, N, N]` , The data type of the input Tensor x
            should be one of float32, float64, complex64, complex128.
        UPLO(str, optional): (string, default 'L'), 'L' represents the lower triangular matrix,
                        "'U' represents the upper triangular matrix.".
        name(str, optional): The default value is None.  Normally there is no need for user to set this
            property.  For more information, please refer to :ref:`api_guide_Name`.

    Returns:
2712 2713 2714 2715
        - out_value(Tensor):  A Tensor with shape [*, N] and data type of float32 and float64.
            The eigenvalues of eigh op.
        - out_vector(Tensor): A Tensor with shape [*, N, N] and data type of float32,float64,
            complex64 and complex128. The eigenvectors of eigh op.
2716 2717 2718 2719 2720 2721

    Examples:
        .. code-block:: python

            import paddle

2722
            x = paddle.to_tensor([[1, -2j], [2j, 5]])
2723
            out_value, out_vector = paddle.linalg.eigh(x, UPLO='L')
2724 2725 2726 2727 2728 2729 2730
            print(out_value)
            #[0.17157288, 5.82842712]
            print(out_vector)
            #[(-0.9238795325112867+0j), (-0.3826834323650898+0j)],
            #[ 0.3826834323650898j    , -0.9238795325112867j    ]]

    """
2731
    if in_dynamic_mode():
2732
        return _C_ops.eigh(x, UPLO)
2733
    else:
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2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749
        def __check_input(x, UPLO):
            x_shape = list(x.shape)
            if len(x.shape) < 2:
                raise ValueError(
                    "Input(input) only support >=2 tensor, but received "
                    "length of Input(input) is %s." % len(x.shape)
                )
            if x_shape[-1] != x_shape[-2]:
                raise ValueError(
                    "The input matrix must be batches of square matrices. But received x's dimention: {}".format(
                        x_shape
                    )
                )
            if UPLO != 'L' and UPLO != 'U':
                raise ValueError(
2750
                    f"UPLO must be L or U. But received UPLO is: {UPLO}"
2751
                )
2752

2753
        __check_input(x, UPLO)
2754

2755 2756 2757 2758 2759 2760 2761
        helper = LayerHelper('eigh', **locals())
        check_variable_and_dtype(
            x,
            'dtype',
            ['float32', 'float64', 'complex64', 'complex128'],
            'eigh',
        )
2762

2763 2764
        out_value = helper.create_variable_for_type_inference(dtype=x.dtype)
        out_vector = helper.create_variable_for_type_inference(dtype=x.dtype)
2765

2766 2767 2768 2769 2770 2771 2772
        helper.append_op(
            type='eigh',
            inputs={'X': x},
            outputs={'Eigenvalues': out_value, 'Eigenvectors': out_vector},
            attrs={'UPLO': UPLO},
        )
        return out_value, out_vector
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def pinv(x, rcond=1e-15, hermitian=False, name=None):
    r"""
2777
    Calculate pseudo inverse via SVD(singular value decomposition)
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2778 2779 2780 2781 2782 2783 2784 2785 2786 2787
    of one matrix or batches of regular matrix.

    .. math::

        if hermitian == False:
            x = u * s * vt  (SVD)
            out = v * 1/s * ut
        else:
            x = u * s * ut  (eigh)
            out = u * 1/s * u.conj().transpose(-2,-1)
2788

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    If x is hermitian or symmetric matrix, svd will be replaced with eigh.

    Args:
2792 2793 2794
        x(Tensor): The input tensor. Its shape should be (*, m, n)
            where * is zero or more batch dimensions. m and n can be
            arbitraty positive number. The data type of x should be
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            float32 or float64 or complex64 or complex128. When data
            type is complex64 or cpmplex128, hermitian should be set
            True.

2799
        rcond(Tensor, optional): the tolerance value to determine
2800
            when is a singular value zero. Default:1e-15.
2801 2802

        hermitian(bool, optional): indicates whether x is Hermitian
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            if complex or symmetric if real. Default: False.
2804 2805

        name(str|None): A name for this layer(optional). If set None,
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            the layer will be named automatically.
2807

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2808
    Returns:
2809
        Tensor: The tensor with same data type with x. it represents
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        pseudo inverse of x. Its shape should be (*, n, m).
2811

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2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837
    Examples:
        .. code-block:: python

            import paddle

            x = paddle.arange(15).reshape((3, 5)).astype('float64')
            input = paddle.to_tensor(x)
            out = paddle.linalg.pinv(input)
            print(input)
            print(out)

            # input:
            # [[0. , 1. , 2. , 3. , 4. ],
            # [5. , 6. , 7. , 8. , 9. ],
            # [10., 11., 12., 13., 14.]]

            # out:
            # [[-0.22666667, -0.06666667,  0.09333333],
            # [-0.12333333, -0.03333333,  0.05666667],
            # [-0.02000000,  0.00000000,  0.02000000],
            # [ 0.08333333,  0.03333333, -0.01666667],
            # [ 0.18666667,  0.06666667, -0.05333333]]

            # one can verify : x * out * x = x ;
            # or              out * x * out = x ;
    """
2838
    if in_dynamic_mode():
2839 2840
        if not hermitian:
            # combine svd and matmul op
2841 2842
            u, s, vt = _C_ops.svd(x, False)
            max_singular_val = _C_ops.max(s, [-1], True)
2843 2844 2845 2846
            rcond = paddle.to_tensor(rcond, dtype=x.dtype)
            cutoff = rcond * max_singular_val
            y = float('inf')
            y = paddle.to_tensor(y, dtype=x.dtype)
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2847

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            singular = paddle.where(s > cutoff, 1 / s, 1 / y)
2849
            st = _C_ops.unsqueeze(singular, [-2])
2850 2851 2852

            dims = list(range(len(vt.shape)))
            perm = dims[:-2] + [dims[-1]] + [dims[-2]]
2853
            v = _C_ops.transpose(vt, perm)
2854 2855

            out_1 = v * st
2856
            out_2 = _C_ops.matmul(out_1, u, False, True)
2857 2858 2859
            return out_2
        else:
            # combine eigh and matmul op
2860
            s, u = _C_ops.eigh(x, 'UPLO')
2861
            s_abs = paddle.abs(s)
2862
            max_singular_val = _C_ops.max(s_abs, [-1], True)
2863 2864 2865 2866 2867
            rcond = paddle.to_tensor(rcond, dtype=s.dtype)
            cutoff = rcond * max_singular_val
            y = float('inf')
            y = paddle.to_tensor(y, dtype=s.dtype)

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            singular = paddle.where(s_abs > cutoff, 1 / s, 1 / y)
2869
            st = _C_ops.unsqueeze(singular, [-2])
2870 2871

            out_1 = u * st
2872 2873
            u_conj = _C_ops.conj(u)
            out_2 = _C_ops.matmul(out_1, u_conj, False, True)
2874
            return out_2
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2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886
    else:
        if not hermitian:
            helper = LayerHelper('pinv', **locals())
            dtype = x.dtype
            check_variable_and_dtype(x, 'x', ['float32', 'float64'], 'pinv')

            u = helper.create_variable_for_type_inference(dtype)
            s = helper.create_variable_for_type_inference(dtype)
            vt = helper.create_variable_for_type_inference(dtype)
            helper.append_op(
                type='svd',
                inputs={'X': [x]},
2887
                outputs={'U': u, 'VH': vt, 'S': s},
2888 2889
                attrs={'full_matrices': False},
            )
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2890 2891

            max_singular_val = helper.create_variable_for_type_inference(dtype)
2892 2893 2894 2895 2896 2897
            helper.append_op(
                type='reduce_max',
                inputs={'X': s},
                outputs={'Out': max_singular_val},
                attrs={'dim': [-1], 'keep_dim': True, 'reduce_all': False},
            )
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2899
            rcond = full(shape=[1], fill_value=rcond, dtype=dtype)
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2900 2901
            cutoff = rcond * max_singular_val
            y = float('inf')
2902
            y = full(shape=[1], fill_value=y, dtype=dtype)
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2903

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2904
            singular = paddle.where(s > cutoff, 1 / s, 1 / y)
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2905 2906 2907

            st = helper.create_variable_for_type_inference(dtype=dtype)
            st_shape = helper.create_variable_for_type_inference(dtype=dtype)
2908 2909 2910 2911 2912 2913
            helper.append_op(
                type='unsqueeze2',
                inputs={'X': singular},
                attrs={'axes': [-2]},
                outputs={'Out': st, 'XShape': st_shape},
            )
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2914 2915 2916 2917 2918

            dims = list(range(len(vt.shape)))
            perm = dims[:-2] + [dims[-1]] + [dims[-2]]
            v = helper.create_variable_for_type_inference(dtype)
            v_shape = helper.create_variable_for_type_inference(dtype)
2919 2920 2921 2922 2923 2924
            helper.append_op(
                type='transpose2',
                inputs={'X': [vt]},
                outputs={'Out': [v], 'XShape': [v_shape]},
                attrs={'axis': perm},
            )
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2925 2926

            out_1 = helper.create_variable_for_type_inference(dtype)
2927 2928 2929 2930 2931 2932
            helper.append_op(
                type='elementwise_mul',
                inputs={'X': v, 'Y': st},
                outputs={'Out': out_1},
                attrs={'axis': -1, 'use_mkldnn': False},
            )
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2933 2934 2935 2936 2937
            out_1 = helper.append_activation(out_1)

            out_2 = helper.create_variable_for_type_inference(dtype)
            helper.append_op(
                type='matmul_v2',
2938
                inputs={'X': out_1, 'Y': u},
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2939
                outputs={'Out': out_2},
2940
                attrs={'trans_x': False, 'trans_y': True},
2941
            )
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2942 2943 2944 2945 2946
            return out_2
        else:
            helper = LayerHelper('pinv', **locals())
            dtype = x.dtype
            check_variable_and_dtype(
2947 2948 2949 2950 2951
                x,
                'dtype',
                ['float32', 'float64', 'complex64', 'complex128'],
                'pinv',
            )
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2952 2953 2954 2955 2956 2957 2958 2959 2960 2961

            if dtype == paddle.complex128:
                s_type = 'float64'
            elif dtype == paddle.complex64:
                s_type = 'float32'
            else:
                s_type = dtype

            u = helper.create_variable_for_type_inference(dtype)
            s = helper.create_variable_for_type_inference(s_type)
2962 2963 2964 2965 2966 2967
            helper.append_op(
                type='eigh',
                inputs={'X': x},
                outputs={'Eigenvalues': s, 'Eigenvectors': u},
                attrs={'UPLO': 'L'},
            )
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2968
            s_abs = helper.create_variable_for_type_inference(s_type)
2969 2970 2971
            helper.append_op(
                type='abs', inputs={'X': s}, outputs={'Out': s_abs}
            )
A
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2972
            max_singular_val = helper.create_variable_for_type_inference(s_type)
2973 2974 2975 2976 2977 2978
            helper.append_op(
                type='reduce_max',
                inputs={'X': s_abs},
                outputs={'Out': max_singular_val},
                attrs={'dim': [-1], 'keep_dim': True, 'reduce_all': False},
            )
A
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2979

2980
            rcond = full(shape=[1], fill_value=rcond, dtype=s_type)
A
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2981 2982
            cutoff = rcond * max_singular_val
            y = float('inf')
2983
            y = full(shape=[1], fill_value=y, dtype=s_type)
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2984

A
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2985
            singular = paddle.where(s_abs > cutoff, 1 / s, 1 / y)
A
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2986 2987 2988

            st = helper.create_variable_for_type_inference(dtype=s_type)
            st_shape = helper.create_variable_for_type_inference(dtype=s_type)
2989 2990 2991 2992 2993 2994
            helper.append_op(
                type='unsqueeze2',
                inputs={'X': singular},
                attrs={'axes': [-2]},
                outputs={'Out': st, 'XShape': st_shape},
            )
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2995 2996

            out_1 = helper.create_variable_for_type_inference(dtype)
2997 2998 2999 3000 3001 3002
            helper.append_op(
                type='elementwise_mul',
                inputs={'X': u, 'Y': st},
                outputs={'Out': out_1},
                attrs={'axis': -1, 'use_mkldnn': False},
            )
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3003 3004 3005
            out_1 = helper.append_activation(out_1)

            u_conj = helper.create_variable_for_type_inference(dtype)
3006 3007 3008
            helper.append_op(
                type='conj', inputs={'X': u}, outputs={'Out': [u_conj]}
            )
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3009 3010 3011 3012

            out_2 = helper.create_variable_for_type_inference(dtype)
            helper.append_op(
                type='matmul_v2',
3013
                inputs={'X': out_1, 'Y': u_conj},
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3014
                outputs={'Out': out_2},
3015
                attrs={'trans_x': False, 'trans_y': True},
3016
            )
A
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3017
            return out_2
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3018 3019 3020 3021


def solve(x, y, name=None):
    r"""
3022

W
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3023
    Computes the solution of a square system of linear equations with a unique solution for input 'X' and 'Y'.
3024
    Let :math:`X` be a sqaure matrix or a batch of square matrices, :math:`Y` be
W
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3025
    a vector/matrix or a batch of vectors/matrices, the equation should be:
3026

W
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3027 3028
    .. math::
        Out = X^-1 * Y
3029 3030

    Specifically, this system of linear equations has one solution if and only if input 'X' is invertible.
3031

W
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3032
    Args:
3033
        x (Tensor): A square matrix or a batch of square matrices. Its shape should be ``[*, M, M]``, where ``*`` is zero or
W
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3034
            more batch dimensions. Its data type should be float32 or float64.
3035
        y (Tensor): A vector/matrix or a batch of vectors/matrices. Its shape should be ``[*, M, K]``, where ``*`` is zero or
W
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3036
            more batch dimensions. Its data type should be float32 or float64.
3037
        name(str, optional): Name for the operation (optional, default is None).
W
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3038
            For more information, please refer to :ref:`api_guide_Name`.
3039

W
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3040
    Returns:
3041
        Tensor: The solution of a square system of linear equations with a unique solution for input 'x' and 'y'.
W
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3042
        Its data type should be the same as that of `x`.
3043

W
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3044
    Examples:
3045

3046
        .. code-block:: python
3047

3048 3049 3050
            # a square system of linear equations:
            # 2*X0 + X1 = 9
            # X0 + 2*X1 = 8
3051

3052 3053 3054 3055 3056
            import paddle

            x = paddle.to_tensor([[3, 1],[1, 2]], dtype="float64")
            y = paddle.to_tensor([9, 8], dtype="float64")
            out = paddle.linalg.solve(x, y)
3057

3058 3059
            print(out)
            # [2., 3.])
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3060
    """
3061
    if in_dynamic_mode():
3062
        return _C_ops.solve(x, y)
3063 3064 3065 3066 3067 3068
    else:
        inputs = {"X": [x], "Y": [y]}
        helper = LayerHelper("solve", **locals())
        check_variable_and_dtype(x, 'x', ['float32', 'float64'], 'solve')
        check_variable_and_dtype(y, 'y', ['float32', 'float64'], 'solve')
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
3069

3070 3071 3072 3073
        helper.append_op(
            type="solve", inputs={"X": x, "Y": y}, outputs={"Out": out}
        )
        return out
3074 3075


3076 3077 3078
def triangular_solve(
    x, y, upper=True, transpose=False, unitriangular=False, name=None
):
3079
    r"""
3080 3081
    Computes the solution of a system of equations with a triangular coefficient.  `x` is coefficient matrix
    `y` is multiple right-hand sides of equations.
3082

3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094
    Input `x` and `y` is 2D matrices or batches of 2D matrices. If the inputs are batches, the outputs is also
    batches.

    Equations can be described as:

    .. math::
        x * Out = y

    Solution of Equations is:

    .. math::
        Out = x ^ {-1} * y
3095 3096 3097 3098

    Args:
        x (Tensor): The input triangular coefficient matrix. Its shape should be `[*, M, M]`, where `*` is zero or
            more batch dimensions. Its data type should be float32 or float64.
3099
        y (Tensor): Multiple right-hand sides of system of equations. Its shape should be `[*, M, K]`, where `*` is
3100
            zero or more batch dimensions. Its data type should be float32 or float64.
3101
        upper (bool, optional): Whether to solve the upper-triangular system of equations (default) or the lower-triangular
3102 3103
            system of equations. Default: True.
        transpose (bool, optional): whether `x` should be transposed before calculation. Default: False.
3104
        unitriangular (bool, optional): whether `x` is unit triangular. If True, the diagonal elements of `x` are assumed
3105 3106 3107 3108 3109 3110 3111 3112
            to be 1 and not referenced from `x` . Default: False.
        name(str, optional): Name for the operation (optional, default is None).
            For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Tensor: The solution of the system of equations. Its data type should be the same as that of `x`.

    Examples:
3113
        .. code-block:: python
3114

3115 3116 3117 3118
            # a square system of linear equations:
            # x1 +   x2  +   x3 = 0
            #      2*x2  +   x3 = -9
            #               -x3 = 5
3119

3120 3121 3122 3123 3124 3125
            import paddle
            x = paddle.to_tensor([[1, 1, 1],
                                  [0, 2, 1],
                                  [0, 0,-1]], dtype="float64")
            y = paddle.to_tensor([[0], [-9], [5]], dtype="float64")
            out = paddle.linalg.triangular_solve(x, y, upper=True)
3126

3127 3128
            print(out)
            # [7, -2, -5]
3129
    """
3130
    if in_dynamic_mode():
3131
        return _C_ops.triangular_solve(x, y, upper, transpose, unitriangular)
3132 3133 3134 3135 3136
    else:
        inputs = {"X": [x], "Y": [y]}
        helper = LayerHelper("triangular_solve", **locals())
        check_variable_and_dtype(
            x, 'x', ['float32', 'float64'], 'triangular_solve'
3137
        )
3138 3139 3140 3141
        check_variable_and_dtype(
            y, 'y', ['float32', 'float64'], 'triangular_solve'
        )
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
3142

3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153
        helper.append_op(
            type='triangular_solve',
            inputs={'X': x, 'Y': y},
            outputs={'Out': out},
            attrs={
                'upper': upper,
                'transpose': transpose,
                'unitriangular': unitriangular,
            },
        )
        return out
3154 3155


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def cholesky_solve(x, y, upper=False, name=None):
    r"""
    Solves a linear system of equations A @ X = B, given A's Cholesky factor matrix u and  matrix B.

    Input `x` and `y` is 2D matrices or batches of 2D matrices. If the inputs are batches, the outputs
    is also batches.

    Args:
3164
        x (Tensor): Multiple right-hand sides of system of equations. Its shape should be `[*, M, K]`, where `*` is
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            zero or more batch dimensions. Its data type should be float32 or float64.
3166 3167
        y (Tensor): The input matrix which is upper or lower triangular Cholesky factor of square matrix A. Its shape should be `[*, M, M]`, where `*` is zero or
            more batch dimensions. Its data type should be float32 or float64.
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        upper (bool, optional): whether to consider the Cholesky factor as a lower or upper triangular matrix. Default: False.
        name(str, optional): Name for the operation (optional, default is None).
            For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Tensor: The solution of the system of equations. Its data type is the same as that of `x`.

    Examples:
3176
        .. code-block:: python
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3178
            import paddle
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            u = paddle.to_tensor([[1, 1, 1],
                                    [0, 2, 1],
                                    [0, 0,-1]], dtype="float64")
            b = paddle.to_tensor([[0], [-9], [5]], dtype="float64")
            out = paddle.linalg.cholesky_solve(b, u, upper=True)
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3186 3187
            print(out)
            # [-2.5, -7, 9.5]
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    """
3189
    if in_dynamic_mode():
3190
        return _C_ops.cholesky_solve(x, y, upper)
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    else:
        helper = LayerHelper("cholesky_solve", **locals())
        check_variable_and_dtype(
            x, 'x', ['float32', 'float64'], 'cholesky_solve'
        )
        check_variable_and_dtype(
            y, 'y', ['float32', 'float64'], 'cholesky_solve'
        )
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
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        helper.append_op(
            type='cholesky_solve',
            inputs={'X': x, 'Y': y},
            outputs={'Out': out},
            attrs={'upper': upper},
        )
        return out
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3210 3211
def eigvalsh(x, UPLO='L', name=None):
    """
3212
    Computes the eigenvalues of a
3213 3214 3215
    complex Hermitian (conjugate symmetric) or a real symmetric matrix.

    Args:
3216
        x (Tensor): A tensor with shape :math:`[*, M, M]` , where * is zero or greater batch dimension. The data type of the input Tensor x
3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229
            should be one of float32, float64, complex64, complex128.
        UPLO(str, optional): Lower triangular part of a (‘L’, default) or the upper triangular part (‘U’).
        name(str, optional): The default value is None.  Normally there is no need for user to set this
            property.  For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Tensor: The tensor eigenvalues in ascending order.

    Examples:
        .. code-block:: python

            import paddle

3230
            x = paddle.to_tensor([[1, -2j], [2j, 5]])
3231 3232
            out_value = paddle.eigvalsh(x, UPLO='L')
            print(out_value)
3233 3234
            # Tensor(shape=[2], dtype=float32, place=Place(cpu), stop_gradient=True,
            #        [0.17157286, 5.82842731])
3235
    """
3236
    if in_dynamic_mode():
3237
        values, _ = _C_ops.eigvalsh(x, UPLO, x.stop_gradient)
3238
        return values
3239
    else:
3240

3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255
        def __check_input(x, UPLO):
            x_shape = list(x.shape)
            if len(x.shape) < 2:
                raise ValueError(
                    "Input(input) only support >=2 tensor, but received "
                    "length of Input(input) is %s." % len(x.shape)
                )
            if x_shape[-1] != x_shape[-2]:
                raise ValueError(
                    "The input matrix must be batches of square matrices. But received x's dimention: {}".format(
                        x_shape
                    )
                )
            if UPLO != 'L' and UPLO != 'U':
                raise ValueError(
3256
                    f"UPLO must be L or U. But received UPLO is: {UPLO}"
3257
                )
3258

3259
        __check_input(x, UPLO)
3260

3261 3262 3263 3264 3265 3266 3267
        helper = LayerHelper('eigvalsh', **locals())
        check_variable_and_dtype(
            x,
            'dtype',
            ['float32', 'float64', 'complex64', 'complex128'],
            'eigvalsh',
        )
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3269 3270
        out_value = helper.create_variable_for_type_inference(dtype=x.dtype)
        out_vector = helper.create_variable_for_type_inference(dtype=x.dtype)
3271

3272 3273 3274 3275 3276 3277 3278 3279
        is_test = x.stop_gradient
        helper.append_op(
            type='eigvalsh',
            inputs={'X': x},
            outputs={'Eigenvalues': out_value, 'Eigenvectors': out_vector},
            attrs={'UPLO': UPLO, 'is_test': is_test},
        )
        return out_value
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3282 3283 3284 3285 3286 3287 3288 3289
def lstsq(x, y, rcond=None, driver=None, name=None):
    """
    Computes a solution to
    the least squares problem of a system of linear equations.

    Args:
        x (Tensor): A tensor with shape ``(*, M, N)`` , the data type of the input Tensor ``x``
            should be one of float32, float64.
3290
        y (Tensor): A tensor with shape ``(*, M, K)`` , the data type of the input Tensor ``y``
3291
            should be one of float32, float64.
3292 3293
        rcond(float, optional): The default value is None. A float pointing number used to determine
            the effective rank of ``x``. If ``rcond`` is None, it will be set to max(M, N) times the
3294
            machine precision of x_dtype.
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        driver(str, optional): The default value is None. The name of LAPACK method to be used. For
            CPU inputs the valid values are ‘gels’, ‘gelsy’, ‘gelsd, ‘gelss’. For CUDA input, the only
            valid driver is ‘gels’. If ``driver`` is None, ‘gelsy’ is used for CPU inputs and ‘gels’
3298
            for CUDA inputs.
3299
        name(str, optional): The default value is None. Normally there is no need for user to set
3300 3301 3302
            this property. For more information, please refer to :ref:`api_guide_Name`.

    Returns:
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        Tuple: A tuple of 4 Tensors which is (``solution``, ``residuals``, ``rank``, ``singular_values``).
        ``solution`` is a tensor with shape ``(*, N, K)``, meaning the least squares solution. ``residuals``
        is a tensor with shape ``(*, K)``, meaning the squared residuals of the solutions, which is computed
        when M > N and every matrix in ``x`` is full-rank, otherwise return an empty tensor. ``rank`` is a tensor
        with shape ``(*)``, meaning the ranks of the matrices in ``x``, which is computed when ``driver`` in
        (‘gelsy’, ‘gelsd’, ‘gelss’), otherwise return an empty tensor. ``singular_values`` is a tensor with
        shape ``(*, min(M, N))``, meaning singular values of the matrices in ``x``, which is computed when
3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341
        ``driver`` in (‘gelsd’, ‘gelss’), otherwise return an empty tensor.

    Examples:
        .. code-block:: python

            import paddle

            paddle.set_device("cpu")
            x = paddle.to_tensor([[1, 3], [3, 2], [5, 6.]])
            y = paddle.to_tensor([[3, 4, 6], [5, 3, 4], [1, 2, 1.]])
            results = paddle.linalg.lstsq(x, y, driver="gelsd")
            print(results[0])
            # [[ 0.78350395, -0.22165027, -0.62371236],
            # [-0.11340097,  0.78866047,  1.14948535]]
            print(results[1])
            # [19.81443405, 10.43814468, 30.56185532])
            print(results[2])
            # 2
            print(results[3])
            # [9.03455734, 1.54167950]

            x = paddle.to_tensor([[10, 2, 3], [3, 10, 5], [5, 6, 12.]])
            y = paddle.to_tensor([[4, 2, 9], [2, 0, 3], [2, 5, 3.]])
            results = paddle.linalg.lstsq(x, y, driver="gels")
            print(results[0])
            # [[ 0.39386186,  0.10230173,  0.93606132],
            # [ 0.10741687, -0.29028133,  0.11892585],
            # [-0.05115091,  0.51918161, -0.19948854]]
            print(results[1])
            # []
    """
    device = paddle.get_device()
3342 3343 3344
    if device == "cpu":
        if driver not in (None, "gels", "gelss", "gelsd", "gelsy"):
            raise ValueError(
3345 3346 3347 3348
                "Only support valid driver is 'gels', 'gelss', 'gelsd', 'gelsy' or None for CPU inputs. But got {}".format(
                    driver
                )
            )
3349 3350 3351 3352
        driver = "gelsy" if driver is None else driver
    elif "gpu" in device:
        if driver not in (None, "gels"):
            raise ValueError(
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                "Only support valid driver is 'gels' or None for CUDA inputs. But got {}".format(
                    driver
                )
            )
3357 3358 3359 3360
        driver = "gels" if driver is None else driver
    else:
        raise RuntimeError("Only support lstsq api for CPU or CUDA device.")

3361
    if not (x.dtype == y.dtype and x.dtype in (paddle.float32, paddle.float64)):
3362 3363 3364 3365
        raise ValueError(
            "Only support x and y have the same dtype such as 'float32' and 'float64'."
        )

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    if x.ndim < 2:
        raise ValueError(
            f"The shape of x should be (*, M, N), but received ndim is [{x.ndim} < 2]"
        )

    if y.ndim < 2:
        raise ValueError(
            f"The shape of y should be (*, M, K), but received ndim is [{y.ndim} < 2]"
        )

    if x.shape[-2] != y.shape[-2]:
        raise ValueError(
            f"x with shape (*, M = {x.shape[-2]}, N) and y with shape (*, M = {y.shape[-2]}, K) should have same M."
        )

3381 3382 3383 3384 3385 3386
    if rcond is None:
        if x.dtype == paddle.float32:
            rcond = 1e-7 * max(x.shape[-2], x.shape[-1])
        elif x.dtype == paddle.float64:
            rcond = 1e-15 * max(x.shape[-2], x.shape[-1])

3387
    if in_dynamic_mode():
3388 3389 3390
        solution, residuals, rank, singular_values = _C_ops.lstsq(
            x, y, rcond, driver
        )
3391 3392 3393 3394 3395 3396 3397
        if driver == "gels":
            rank = paddle.empty(shape=[0], dtype=paddle.int32)
            singular_values = paddle.empty(shape=[0], dtype=x.dtype)
        elif driver == "gelsy":
            singular_values = paddle.empty(shape=[0], dtype=x.dtype)

        return solution, residuals, rank, singular_values
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    else:
        helper = LayerHelper('lstsq', **locals())
        check_variable_and_dtype(
            x,
            'dtype',
            ['float32', 'float64', 'complex64', 'complex128'],
            'lstsq',
        )
        check_variable_and_dtype(
            y,
            'dtype',
            ['float32', 'float64', 'complex64', 'complex128'],
            'lstsq',
        )
3412

3413 3414 3415 3416 3417 3418
        solution = helper.create_variable_for_type_inference(dtype=x.dtype)
        residuals = helper.create_variable_for_type_inference(dtype=x.dtype)
        rank = helper.create_variable_for_type_inference(dtype=paddle.int32)
        singular_values = helper.create_variable_for_type_inference(
            dtype=x.dtype
        )
3419

3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430
        helper.append_op(
            type='lstsq',
            inputs={'X': x, 'Y': y},
            outputs={
                'Solution': solution,
                'Residuals': residuals,
                'Rank': rank,
                'SingularValues': singular_values,
            },
            attrs={'rcond': rcond, 'driver': driver},
        )
3431

3432 3433 3434 3435 3436 3437 3438 3439 3440
        if driver == "gels":
            rank = paddle.static.data(name='rank', shape=[0])
            singular_values = paddle.static.data(
                name='singular_values', shape=[0]
            )
        elif driver == "gelsy":
            singular_values = paddle.static.data(
                name='singular_values', shape=[0]
            )
3441

3442
        return solution, residuals, rank, singular_values
3443 3444 3445 3446


def corrcoef(x, rowvar=True, name=None):
    """
3447

3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470
    A correlation coefficient matrix indicate the correlation of each pair variables in the input matrix.
    For example, for an N-dimensional samples X=[x1,x2,…xN]T, then the correlation coefficient matrix
    element Rij is the correlation of xi and xj. The element Rii is the covariance of xi itself.

    The relationship between the correlation coefficient matrix `R` and the
    covariance matrix `C`, is

    .. math:: R_{ij} = \\frac{ C_{ij} } { \\sqrt{ C_{ii} * C_{jj} } }

    The values of `R` are between -1 and 1.

    Parameters:

        x(Tensor): A N-D(N<=2) Tensor containing multiple variables and observations. By default, each row of x represents a variable. Also see rowvar below.
        rowvar(Bool, optional): If rowvar is True (default), then each row represents a variable, with observations in the columns. Default: True.
        name(str, optional): Name of the output. Default is None. It's used to print debug info for developers. Details: :ref:`api_guide_Name`.

    Returns:

        The correlation coefficient matrix of the variables.

    Examples:
        .. code-block:: python
3471

3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485
            import paddle

            xt = paddle.rand((3,4))
            print(paddle.linalg.corrcoef(xt))

            # Tensor(shape=[3, 3], dtype=float32, place=Place(cpu), stop_gradient=True,
            # [[ 1.        , -0.73702252,  0.66228950],
            # [-0.73702258,  1.        , -0.77104872],
            # [ 0.66228974, -0.77104825,  1.        ]])

    """
    if len(x.shape) > 2 or len(x.shape) < 1:
        raise ValueError(
            "Input(x) only support N-D (1<=N<=2) tensor in corrcoef, but received "
3486 3487
            "length of Input(input) is %s." % len(x.shape)
        )
3488 3489 3490
    check_variable_and_dtype(x, 'dtype', ['float32', 'float64'], 'corrcoef')

    c = cov(x, rowvar)
3491
    if c.ndim == 0:
3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505
        # scalar covariance
        # nan if incorrect value (nan, inf, 0), 1 otherwise
        return c / c

    d = paddle.diag(c)

    if paddle.is_complex(d):
        d = d.real()
    stddev = paddle.sqrt(d)
    c /= stddev[:, None]
    c /= stddev[None, :]

    # Clip to [-1, 1].  This does not guarantee
    if paddle.is_complex(c):
3506 3507 3508
        return paddle.complex(
            paddle.clip(c.real(), -1, 1), paddle.clip(c.imag(), -1, 1)
        )
3509 3510 3511 3512
    else:
        c = paddle.clip(c, -1, 1)

    return c
3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628


def cdist(
    x, y, p=2.0, compute_mode="use_mm_for_euclid_dist_if_necessary", name=None
):
    r"""

    Compute the p-norm distance between each pair of the two collections of inputs.

    This function is equivalent to `scipy.spatial.distance.cdist(input,'minkowski', p=p)`
    if :math:`p \in (0, \infty)`. When :math:`p = 0` it is equivalent to `scipy.spatial.distance.cdist(input, 'hamming') * M`.
    When :math:`p = \infty`, the closest scipy function is `scipy.spatial.distance.cdist(xn, lambda x, y: np.abs(x - y).max())`.

    Args:
        x (Tensor): A tensor with shape :math:`B \times P \times M`.
        y (Tensor): A tensor with shape :math:`B \times R \times M`.
        p (float, optional): The value for the p-norm distance to calculate between each vector pair. Default: :math:`2.0`.
        compute_mode (str, optional): The mode for compute distance.

            - ``use_mm_for_euclid_dist_if_necessary`` , for p = 2.0 and (P > 25 or R > 25), it will use matrix multiplication to calculate euclid distance if possible.
            - ``use_mm_for_euclid_dist`` , for p = 2.0, it will use matrix multiplication to calculate euclid distance.
            - ``donot_use_mm_for_euclid_dist`` , it will not use matrix multiplication to calculate euclid distance.

            Default: ``use_mm_for_euclid_dist_if_necessary``.
        name (str, optional): For details, please refer to :ref:`api_guide_Name`. Generally, no setting is required. Default: None.

    Returns:
        Tensor, the dtype is same as input tensor.

        If x has shape :math:`B \times P \times M` and y has shape :math:`B \times R \times M` then
        the output will have shape :math:`B \times P \times R`.

    Examples:
        .. code-block:: python

            import paddle
            x = paddle.to_tensor([[0.9041,  0.0196], [-0.3108, -2.4423], [-0.4821,  1.059]], dtype=paddle.float32)
            y = paddle.to_tensor([[-2.1763, -0.4713], [-0.6986,  1.3702]], dtype=paddle.float32)
            distance = paddle.cdist(x, y)
            print(distance)
            # Tensor(shape=[3, 2], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            # [[3.1193, 2.0959], [2.7138, 3.8322], [2.2830, 0.3791]])
    """

    check_variable_and_dtype(x, 'x', ('float32', 'float64'), 'cdist')
    check_variable_and_dtype(y, 'y', ('float32', 'float64'), 'cdist')
    check_type(p, 'p', (float, int), 'cdist')

    if compute_mode not in [
        'use_mm_for_euclid_dist_if_necessary',
        'use_mm_for_euclid_dist',
        'donot_use_mm_for_euclid_dist',
    ]:
        raise ValueError(
            "The compute_mode should be 'use_mm_for_euclid_dist_if_necessary', "
            "'use_mm_for_euclid_dist' or 'donot_use_mm_for_euclid_dist', "
            "but received compute_mode is %s." % compute_mode
        )

    mode = 0
    if compute_mode == 'use_mm_for_euclid_dist_if_necessary':
        mode = 0
    elif compute_mode == 'use_mm_for_euclid_dist':
        mode = 1
    elif compute_mode == 'donot_use_mm_for_euclid_dist':
        mode = 2

    x_shape = list(x.shape)
    assert len(x_shape) >= 2, (
        "The x must be at least 2-dimensional, "
        "But received Input x's dimensional is %s.\n" % len(x_shape)
    )
    y_shape = list(y.shape)
    assert len(y_shape) >= 2, (
        "The y must be at least 2-dimensional, "
        "But received Input y's dimensional is %s.\n" % len(y_shape)
    )
    assert x_shape[-1] == y_shape[-1], (
        "The x and y must have same last dimension, "
        "But received Input x's last dimension is {}, "
        "Input y's last dimension is {}.\n".format(x_shape[-1], y_shape[-1])
    )
    assert p >= 0, (
        "The p must be greater than or equal to 0, "
        "But received p is %s.\n" % p
    )

    r1 = x.shape[-2]
    r2 = y.shape[-2]
    c1 = x.shape[-1]

    p = float(p)

    if r1 == 0 or r2 == 0:
        return paddle.empty((r1, r2), dtype=x.dtype)

    if c1 == 0:
        return paddle.zeros((r1, r2), dtype=x.dtype)

    if p == 2.0 and (mode == 1 or (mode == 0 and (r1 > 25 or r2 > 25))):
        x_norm = paddle.sum(x.pow(2), axis=-1, keepdim=True)
        y_norm = paddle.sum(y.pow(2), axis=-1, keepdim=True)
        y_transposed = paddle.transpose(
            y, perm=[*range(y.ndim - 2), y.ndim - 1, y.ndim - 2]
        )
        y_norm_transposed = paddle.transpose(
            y_norm,
            perm=[*range(y_norm.ndim - 2), y_norm.ndim - 1, y_norm.ndim - 2],
        )
        res = paddle.matmul(x, y_transposed) * -2 + y_norm_transposed + x_norm
        res = paddle.clip(res, min=0.0).sqrt()
        return res

    return paddle.linalg.norm(
        x[..., None, :] - y[..., None, :, :], p=p, axis=-1
    )